NCERT Textbook: Health and Diseases | Health and Physical Education for Class 9 PDF Download

 Page 1


Health and Diseases
1
1.1  IntroductIon We normally relate the terms diseases and illness 
interchangeably in relation to health, even though these 
words do not mean the same. Health is the general condition 
of a person in respect to all aspects of life. It is also a level 
of functional and/or metabolic efficiency of an organism. The 
word metabolic is the adjective of the term metabolism which 
means the whole range of big chemical processes that occur 
within us or any living organism to produce energy and basic 
materials needed for important life processes. Diseases and 
illness adversely affect these processes. And thus health, 
diseases and illness are inter-related. However,   health is not 
just being free from diseases, illness or injury.  As defined 
by World Health Organisation (WHO), health is “a state of 
complete physical, mental and social well-being and not merely 
an absence of disease or infirmity”. 
1.2  What Is Illness ?
Let’s now see how is illness different from that of disease? 
While illness and disease are at times used interchangeably, 
these in fact, are different from each other. Disease refers to a 
biomedically defined deviation from norms of body function or 
structure, whereas, illness is the experience of this deviation. 
It is a state of experience by the body when one or more of 
the control systems of the body are not functioning normally. 
Illness refers to a subjective distress  feeling of a person, when 
one is sick or suffering from some disease.  However, it is not 
appropriate to conclude that any one being merely free from 
illness or disease is healthy.
You might have seen people suffering from various types of 
diseases. Some of the diseases, like high blood pressure affect 
only a particular person who is suffering from it. On the other 
hand, some diseases like common cold, spread rapidly and 
affect a number of people in a very short period. You must 
have often wondered as to how does this happen. In one of the 
chapters of your textbook on Science, you would have studied 
about ‘Why We Fall Ill’. In that chapter, it is mentioned how 
diseases are caused and how some of these affect only the 
persons who suffer from them are called non-communicable, 
whereas, there are those diseases that are transmitted from one 
Page 2


Health and Diseases
1
1.1  IntroductIon We normally relate the terms diseases and illness 
interchangeably in relation to health, even though these 
words do not mean the same. Health is the general condition 
of a person in respect to all aspects of life. It is also a level 
of functional and/or metabolic efficiency of an organism. The 
word metabolic is the adjective of the term metabolism which 
means the whole range of big chemical processes that occur 
within us or any living organism to produce energy and basic 
materials needed for important life processes. Diseases and 
illness adversely affect these processes. And thus health, 
diseases and illness are inter-related. However,   health is not 
just being free from diseases, illness or injury.  As defined 
by World Health Organisation (WHO), health is “a state of 
complete physical, mental and social well-being and not merely 
an absence of disease or infirmity”. 
1.2  What Is Illness ?
Let’s now see how is illness different from that of disease? 
While illness and disease are at times used interchangeably, 
these in fact, are different from each other. Disease refers to a 
biomedically defined deviation from norms of body function or 
structure, whereas, illness is the experience of this deviation. 
It is a state of experience by the body when one or more of 
the control systems of the body are not functioning normally. 
Illness refers to a subjective distress  feeling of a person, when 
one is sick or suffering from some disease.  However, it is not 
appropriate to conclude that any one being merely free from 
illness or disease is healthy.
You might have seen people suffering from various types of 
diseases. Some of the diseases, like high blood pressure affect 
only a particular person who is suffering from it. On the other 
hand, some diseases like common cold, spread rapidly and 
affect a number of people in a very short period. You must 
have often wondered as to how does this happen. In one of the 
chapters of your textbook on Science, you would have studied 
about ‘Why We Fall Ill’. In that chapter, it is mentioned how 
diseases are caused and how some of these affect only the 
persons who suffer from them are called non-communicable, 
whereas, there are those diseases that are transmitted from one 
 Health and Physical Education — Class IX
person to another are known as communicable. The chapter 
also mentions how communicable and non-communicable 
diseases can be prevented and controlled. 
1.3  c ommunIcable d Iseases 
Let us understand how communicable diseases are spread. These 
diseases are caused by certain infectious agents which may be 
bacteria or viruses. These are capable of being transmitted from 
person to person or from the environment to person.
1.3.1 Classification  
Communicable diseases can be classified on the basis of the 
causative organisms. These are as follow:
•	 Bacterial: Typhoid, Cholera, Tuberculosis
•	 Viral: Common cold, Influenza, HIV infection, Dengue
•	 Protozoal: Malaria, Kala azar
•	 Fungal: Fungal infections of nails, groins, skin, hair
•	 Parasitic: Infestations of intestinal worms, like round  
worm, or lice.
Modes of transmission: The modes of transmission can be 
classified as direct and indirect transmission. 
(a) Direct transmission
As we have studied in our earlier classes, direct transmission 
of diseases takes place as follows:
Direct contact or touching: When we touch a person or 
come in direct contact with the skin or mucous membrane of 
the diseased person, it transmits infections like skin and eye 
infection.
Droplet infection:  Spray of droplets of saliva or secretion 
of a diseased person spreads common cold, tuberculosis, 
meningitis.
Contact with soil: Can cause acquiring the disease agent 
directly and may spread diseases like: hookworm infestation 
and tetanus.
Inoculation into skin or mucosa: Certain diseases 
spread in other ways. For example, Rabies is spread to 
humans from animal. It is generally known that it occurs due 
to a dog or a monkey bite. Hepatitis occurs owing to virus, 
transmitted through contaminated needles. The HIV (Human 
Immunodeficiency Virus) can be transmitted by sexual contact 
or through transmission of infected blood from an infected 
person. HIV can be transmitted by the HIV infected mother 
to baby and can cause AIDS (Acquired Immune Deficiency 
Syndrome).
a ctIvIty 1.1
Discuss with your 
classmates, why 
we should not go to 
public places when 
suffering from cold, 
cough or fever?
Page 3


Health and Diseases
1
1.1  IntroductIon We normally relate the terms diseases and illness 
interchangeably in relation to health, even though these 
words do not mean the same. Health is the general condition 
of a person in respect to all aspects of life. It is also a level 
of functional and/or metabolic efficiency of an organism. The 
word metabolic is the adjective of the term metabolism which 
means the whole range of big chemical processes that occur 
within us or any living organism to produce energy and basic 
materials needed for important life processes. Diseases and 
illness adversely affect these processes. And thus health, 
diseases and illness are inter-related. However,   health is not 
just being free from diseases, illness or injury.  As defined 
by World Health Organisation (WHO), health is “a state of 
complete physical, mental and social well-being and not merely 
an absence of disease or infirmity”. 
1.2  What Is Illness ?
Let’s now see how is illness different from that of disease? 
While illness and disease are at times used interchangeably, 
these in fact, are different from each other. Disease refers to a 
biomedically defined deviation from norms of body function or 
structure, whereas, illness is the experience of this deviation. 
It is a state of experience by the body when one or more of 
the control systems of the body are not functioning normally. 
Illness refers to a subjective distress  feeling of a person, when 
one is sick or suffering from some disease.  However, it is not 
appropriate to conclude that any one being merely free from 
illness or disease is healthy.
You might have seen people suffering from various types of 
diseases. Some of the diseases, like high blood pressure affect 
only a particular person who is suffering from it. On the other 
hand, some diseases like common cold, spread rapidly and 
affect a number of people in a very short period. You must 
have often wondered as to how does this happen. In one of the 
chapters of your textbook on Science, you would have studied 
about ‘Why We Fall Ill’. In that chapter, it is mentioned how 
diseases are caused and how some of these affect only the 
persons who suffer from them are called non-communicable, 
whereas, there are those diseases that are transmitted from one 
 Health and Physical Education — Class IX
person to another are known as communicable. The chapter 
also mentions how communicable and non-communicable 
diseases can be prevented and controlled. 
1.3  c ommunIcable d Iseases 
Let us understand how communicable diseases are spread. These 
diseases are caused by certain infectious agents which may be 
bacteria or viruses. These are capable of being transmitted from 
person to person or from the environment to person.
1.3.1 Classification  
Communicable diseases can be classified on the basis of the 
causative organisms. These are as follow:
•	 Bacterial: Typhoid, Cholera, Tuberculosis
•	 Viral: Common cold, Influenza, HIV infection, Dengue
•	 Protozoal: Malaria, Kala azar
•	 Fungal: Fungal infections of nails, groins, skin, hair
•	 Parasitic: Infestations of intestinal worms, like round  
worm, or lice.
Modes of transmission: The modes of transmission can be 
classified as direct and indirect transmission. 
(a) Direct transmission
As we have studied in our earlier classes, direct transmission 
of diseases takes place as follows:
Direct contact or touching: When we touch a person or 
come in direct contact with the skin or mucous membrane of 
the diseased person, it transmits infections like skin and eye 
infection.
Droplet infection:  Spray of droplets of saliva or secretion 
of a diseased person spreads common cold, tuberculosis, 
meningitis.
Contact with soil: Can cause acquiring the disease agent 
directly and may spread diseases like: hookworm infestation 
and tetanus.
Inoculation into skin or mucosa: Certain diseases 
spread in other ways. For example, Rabies is spread to 
humans from animal. It is generally known that it occurs due 
to a dog or a monkey bite. Hepatitis occurs owing to virus, 
transmitted through contaminated needles. The HIV (Human 
Immunodeficiency Virus) can be transmitted by sexual contact 
or through transmission of infected blood from an infected 
person. HIV can be transmitted by the HIV infected mother 
to baby and can cause AIDS (Acquired Immune Deficiency 
Syndrome).
a ctIvIty 1.1
Discuss with your 
classmates, why 
we should not go to 
public places when 
suffering from cold, 
cough or fever?
Health and Diseases 
(b) Indirect transmission
Communicable diseases are also transmitted indirectly in 
the following ways that are popularly known as ‘5Fs’— flies, 
fingers, fomites (material capable of carrying infections, like 
towels, handkarchiefs etc.), food and fluid.  
Some diseases are spread through water, food, ice, blood 
and body tissues and organs. For example, typhoid, diarrhoea, 
polio, intestinal parasites and infective hepatitis. Flies 
contaminate food and other eatables.
A living carrier (also known as a vector) is a disease 
agent that lives on or inside the body of the carrier causing 
diseases like malaria and plague. Airborne infectious materials 
transmitted through droplet infection or dust cause diseases 
like respiratory infections and itch mites. Fomites are objects 
like towels, handkerchiefs, toys, glass, spoons, etc. which we 
use daily. Eye and skin infections and dysentery (diarrhoea 
with blood) are spread through these fomites. Our unclean 
hands and fingers act as disease causing agents and transfer 
infection to food through skin, nose, and causes diseases, such 
as intestinal parasites, dysentery, typhoid. 
Healthy people can also spread disease if they are “carriers”.  
These are the people who themselves may be immune to the 
organisms they harbour, but can be a source of transmission 
to others as happens in the case of typhoid.  
1.3.2 Prevention  and  Control  of  Communicable Diseases
The following measures help in prevention and control the 
spread of communicable diseases:
Personal hygiene
•	 Bathing everyday and clean clothes keep our body free 
from harmful microbes.
•	 Cutting nails and washing hair regularly.
•	 Brushing teeth twice a day (morning and night) 
particularly after meals. 
•	 Ensuring that your ears are clean. 
•	 Do not share articles that are of personal use, that is, 
towels, soaps, tooth brushes, combs, razors and other 
toiletries. 
•	 Wash hands before touching food or water and before 
eating or drinking.
•	 Wash hands with soap and water before touching your 
face, eyes and mouth and also before and after using 
the toilet. 
•	 Many microbes like virus, bacteria and fungi are 
transmitted by touching surfaces with hands and 
a ctIvIty 1.2
•	 List how many 
things you follow 
for food and 
water hygiene 
•	 Discuss the list 
with your friend.
•	 What would 
you like to do 
to improve your 
personal hygiene.
Page 4


Health and Diseases
1
1.1  IntroductIon We normally relate the terms diseases and illness 
interchangeably in relation to health, even though these 
words do not mean the same. Health is the general condition 
of a person in respect to all aspects of life. It is also a level 
of functional and/or metabolic efficiency of an organism. The 
word metabolic is the adjective of the term metabolism which 
means the whole range of big chemical processes that occur 
within us or any living organism to produce energy and basic 
materials needed for important life processes. Diseases and 
illness adversely affect these processes. And thus health, 
diseases and illness are inter-related. However,   health is not 
just being free from diseases, illness or injury.  As defined 
by World Health Organisation (WHO), health is “a state of 
complete physical, mental and social well-being and not merely 
an absence of disease or infirmity”. 
1.2  What Is Illness ?
Let’s now see how is illness different from that of disease? 
While illness and disease are at times used interchangeably, 
these in fact, are different from each other. Disease refers to a 
biomedically defined deviation from norms of body function or 
structure, whereas, illness is the experience of this deviation. 
It is a state of experience by the body when one or more of 
the control systems of the body are not functioning normally. 
Illness refers to a subjective distress  feeling of a person, when 
one is sick or suffering from some disease.  However, it is not 
appropriate to conclude that any one being merely free from 
illness or disease is healthy.
You might have seen people suffering from various types of 
diseases. Some of the diseases, like high blood pressure affect 
only a particular person who is suffering from it. On the other 
hand, some diseases like common cold, spread rapidly and 
affect a number of people in a very short period. You must 
have often wondered as to how does this happen. In one of the 
chapters of your textbook on Science, you would have studied 
about ‘Why We Fall Ill’. In that chapter, it is mentioned how 
diseases are caused and how some of these affect only the 
persons who suffer from them are called non-communicable, 
whereas, there are those diseases that are transmitted from one 
 Health and Physical Education — Class IX
person to another are known as communicable. The chapter 
also mentions how communicable and non-communicable 
diseases can be prevented and controlled. 
1.3  c ommunIcable d Iseases 
Let us understand how communicable diseases are spread. These 
diseases are caused by certain infectious agents which may be 
bacteria or viruses. These are capable of being transmitted from 
person to person or from the environment to person.
1.3.1 Classification  
Communicable diseases can be classified on the basis of the 
causative organisms. These are as follow:
•	 Bacterial: Typhoid, Cholera, Tuberculosis
•	 Viral: Common cold, Influenza, HIV infection, Dengue
•	 Protozoal: Malaria, Kala azar
•	 Fungal: Fungal infections of nails, groins, skin, hair
•	 Parasitic: Infestations of intestinal worms, like round  
worm, or lice.
Modes of transmission: The modes of transmission can be 
classified as direct and indirect transmission. 
(a) Direct transmission
As we have studied in our earlier classes, direct transmission 
of diseases takes place as follows:
Direct contact or touching: When we touch a person or 
come in direct contact with the skin or mucous membrane of 
the diseased person, it transmits infections like skin and eye 
infection.
Droplet infection:  Spray of droplets of saliva or secretion 
of a diseased person spreads common cold, tuberculosis, 
meningitis.
Contact with soil: Can cause acquiring the disease agent 
directly and may spread diseases like: hookworm infestation 
and tetanus.
Inoculation into skin or mucosa: Certain diseases 
spread in other ways. For example, Rabies is spread to 
humans from animal. It is generally known that it occurs due 
to a dog or a monkey bite. Hepatitis occurs owing to virus, 
transmitted through contaminated needles. The HIV (Human 
Immunodeficiency Virus) can be transmitted by sexual contact 
or through transmission of infected blood from an infected 
person. HIV can be transmitted by the HIV infected mother 
to baby and can cause AIDS (Acquired Immune Deficiency 
Syndrome).
a ctIvIty 1.1
Discuss with your 
classmates, why 
we should not go to 
public places when 
suffering from cold, 
cough or fever?
Health and Diseases 
(b) Indirect transmission
Communicable diseases are also transmitted indirectly in 
the following ways that are popularly known as ‘5Fs’— flies, 
fingers, fomites (material capable of carrying infections, like 
towels, handkarchiefs etc.), food and fluid.  
Some diseases are spread through water, food, ice, blood 
and body tissues and organs. For example, typhoid, diarrhoea, 
polio, intestinal parasites and infective hepatitis. Flies 
contaminate food and other eatables.
A living carrier (also known as a vector) is a disease 
agent that lives on or inside the body of the carrier causing 
diseases like malaria and plague. Airborne infectious materials 
transmitted through droplet infection or dust cause diseases 
like respiratory infections and itch mites. Fomites are objects 
like towels, handkerchiefs, toys, glass, spoons, etc. which we 
use daily. Eye and skin infections and dysentery (diarrhoea 
with blood) are spread through these fomites. Our unclean 
hands and fingers act as disease causing agents and transfer 
infection to food through skin, nose, and causes diseases, such 
as intestinal parasites, dysentery, typhoid. 
Healthy people can also spread disease if they are “carriers”.  
These are the people who themselves may be immune to the 
organisms they harbour, but can be a source of transmission 
to others as happens in the case of typhoid.  
1.3.2 Prevention  and  Control  of  Communicable Diseases
The following measures help in prevention and control the 
spread of communicable diseases:
Personal hygiene
•	 Bathing everyday and clean clothes keep our body free 
from harmful microbes.
•	 Cutting nails and washing hair regularly.
•	 Brushing teeth twice a day (morning and night) 
particularly after meals. 
•	 Ensuring that your ears are clean. 
•	 Do not share articles that are of personal use, that is, 
towels, soaps, tooth brushes, combs, razors and other 
toiletries. 
•	 Wash hands before touching food or water and before 
eating or drinking.
•	 Wash hands with soap and water before touching your 
face, eyes and mouth and also before and after using 
the toilet. 
•	 Many microbes like virus, bacteria and fungi are 
transmitted by touching surfaces with hands and 
a ctIvIty 1.2
•	 List how many 
things you follow 
for food and 
water hygiene 
•	 Discuss the list 
with your friend.
•	 What would 
you like to do 
to improve your 
personal hygiene.
 Health and Physical Education — Class IX
become potential carriers. Hence by washing hands, we 
can prevent diseases like diarrhoea, flu, skin and eye 
infections.
Food and water hygiene
•	 Drink potable water. If it does not appear clean, boil or 
filter and then consume it. 
•	 Eat only freshly prepared food or consume it within four 
hours of preparation. 
•	 Do not purchase and consume fruits and vegetables 
which have been cut and kept in the open for a long 
time. 
•	 Keep all food articles covered to prevent contamination 
by flies.
Environmental sanitation
•	 Use sanitary latrines; avoid open air defecation. 
•	 Throw waste in dustbins to avoid breeding of flies. 
•	 Clean the drains regularly.
•	 Regularly check the places where water is collected 
and has the possibilities of mosquito breeding. Spray 
insecticide to prevent breeding of mosquitoes. 
•	 Try to prevent contamination of drinking water (source of 
water should be away from source of garbage collection/
waste disposal site). The container of drinking water 
must be kept at a clean and safe place.
Vaccines 
Vaccines boost immunity and thus helps the body fight diseases. 
A large number of infectious diseases can be prevented by 
taking vaccines at an appropriate time, such as, diphtheria, 
pertussis, polio, tetanus, rabies, measles, chickenpox, typhoid, 
etc.
Treatment of diseases using medicines 
Medicines kill microbes and /or slow their growth. These are 
classified as anti-virals, anti-fungals, anti-protozoals and 
antibiotics according to the group of microbes they act upon.  
However, these medicines should be taken in the recommended 
dose and duration as advised by the doctor. One should avoid 
self-medication.
Isolation of patients with communicable diseases
Patients suffering from such diseases that are communicable 
should be kept in a clean environment isolated from others.
Education and awareness
It is important to make people aware about communicable 
diseases, their causes and modes of spread.  People should 
a ctIvIty 1.3
Have a round of your 
school. Find out 
the environmetnal 
sanitation.
Discuss with 
your classmates. 
If it is not good 
what will you do? 
Prepare a plan and 
implement.
a ctIvIty 1.4
Prepare an 
Immunisation 
chart. Put it in 
your classroom. 
Discuss with your 
classmates whether 
everyone has been 
vaccinated? If not, 
request them to 
consult a nearby 
health centre.
Page 5


Health and Diseases
1
1.1  IntroductIon We normally relate the terms diseases and illness 
interchangeably in relation to health, even though these 
words do not mean the same. Health is the general condition 
of a person in respect to all aspects of life. It is also a level 
of functional and/or metabolic efficiency of an organism. The 
word metabolic is the adjective of the term metabolism which 
means the whole range of big chemical processes that occur 
within us or any living organism to produce energy and basic 
materials needed for important life processes. Diseases and 
illness adversely affect these processes. And thus health, 
diseases and illness are inter-related. However,   health is not 
just being free from diseases, illness or injury.  As defined 
by World Health Organisation (WHO), health is “a state of 
complete physical, mental and social well-being and not merely 
an absence of disease or infirmity”. 
1.2  What Is Illness ?
Let’s now see how is illness different from that of disease? 
While illness and disease are at times used interchangeably, 
these in fact, are different from each other. Disease refers to a 
biomedically defined deviation from norms of body function or 
structure, whereas, illness is the experience of this deviation. 
It is a state of experience by the body when one or more of 
the control systems of the body are not functioning normally. 
Illness refers to a subjective distress  feeling of a person, when 
one is sick or suffering from some disease.  However, it is not 
appropriate to conclude that any one being merely free from 
illness or disease is healthy.
You might have seen people suffering from various types of 
diseases. Some of the diseases, like high blood pressure affect 
only a particular person who is suffering from it. On the other 
hand, some diseases like common cold, spread rapidly and 
affect a number of people in a very short period. You must 
have often wondered as to how does this happen. In one of the 
chapters of your textbook on Science, you would have studied 
about ‘Why We Fall Ill’. In that chapter, it is mentioned how 
diseases are caused and how some of these affect only the 
persons who suffer from them are called non-communicable, 
whereas, there are those diseases that are transmitted from one 
 Health and Physical Education — Class IX
person to another are known as communicable. The chapter 
also mentions how communicable and non-communicable 
diseases can be prevented and controlled. 
1.3  c ommunIcable d Iseases 
Let us understand how communicable diseases are spread. These 
diseases are caused by certain infectious agents which may be 
bacteria or viruses. These are capable of being transmitted from 
person to person or from the environment to person.
1.3.1 Classification  
Communicable diseases can be classified on the basis of the 
causative organisms. These are as follow:
•	 Bacterial: Typhoid, Cholera, Tuberculosis
•	 Viral: Common cold, Influenza, HIV infection, Dengue
•	 Protozoal: Malaria, Kala azar
•	 Fungal: Fungal infections of nails, groins, skin, hair
•	 Parasitic: Infestations of intestinal worms, like round  
worm, or lice.
Modes of transmission: The modes of transmission can be 
classified as direct and indirect transmission. 
(a) Direct transmission
As we have studied in our earlier classes, direct transmission 
of diseases takes place as follows:
Direct contact or touching: When we touch a person or 
come in direct contact with the skin or mucous membrane of 
the diseased person, it transmits infections like skin and eye 
infection.
Droplet infection:  Spray of droplets of saliva or secretion 
of a diseased person spreads common cold, tuberculosis, 
meningitis.
Contact with soil: Can cause acquiring the disease agent 
directly and may spread diseases like: hookworm infestation 
and tetanus.
Inoculation into skin or mucosa: Certain diseases 
spread in other ways. For example, Rabies is spread to 
humans from animal. It is generally known that it occurs due 
to a dog or a monkey bite. Hepatitis occurs owing to virus, 
transmitted through contaminated needles. The HIV (Human 
Immunodeficiency Virus) can be transmitted by sexual contact 
or through transmission of infected blood from an infected 
person. HIV can be transmitted by the HIV infected mother 
to baby and can cause AIDS (Acquired Immune Deficiency 
Syndrome).
a ctIvIty 1.1
Discuss with your 
classmates, why 
we should not go to 
public places when 
suffering from cold, 
cough or fever?
Health and Diseases 
(b) Indirect transmission
Communicable diseases are also transmitted indirectly in 
the following ways that are popularly known as ‘5Fs’— flies, 
fingers, fomites (material capable of carrying infections, like 
towels, handkarchiefs etc.), food and fluid.  
Some diseases are spread through water, food, ice, blood 
and body tissues and organs. For example, typhoid, diarrhoea, 
polio, intestinal parasites and infective hepatitis. Flies 
contaminate food and other eatables.
A living carrier (also known as a vector) is a disease 
agent that lives on or inside the body of the carrier causing 
diseases like malaria and plague. Airborne infectious materials 
transmitted through droplet infection or dust cause diseases 
like respiratory infections and itch mites. Fomites are objects 
like towels, handkerchiefs, toys, glass, spoons, etc. which we 
use daily. Eye and skin infections and dysentery (diarrhoea 
with blood) are spread through these fomites. Our unclean 
hands and fingers act as disease causing agents and transfer 
infection to food through skin, nose, and causes diseases, such 
as intestinal parasites, dysentery, typhoid. 
Healthy people can also spread disease if they are “carriers”.  
These are the people who themselves may be immune to the 
organisms they harbour, but can be a source of transmission 
to others as happens in the case of typhoid.  
1.3.2 Prevention  and  Control  of  Communicable Diseases
The following measures help in prevention and control the 
spread of communicable diseases:
Personal hygiene
•	 Bathing everyday and clean clothes keep our body free 
from harmful microbes.
•	 Cutting nails and washing hair regularly.
•	 Brushing teeth twice a day (morning and night) 
particularly after meals. 
•	 Ensuring that your ears are clean. 
•	 Do not share articles that are of personal use, that is, 
towels, soaps, tooth brushes, combs, razors and other 
toiletries. 
•	 Wash hands before touching food or water and before 
eating or drinking.
•	 Wash hands with soap and water before touching your 
face, eyes and mouth and also before and after using 
the toilet. 
•	 Many microbes like virus, bacteria and fungi are 
transmitted by touching surfaces with hands and 
a ctIvIty 1.2
•	 List how many 
things you follow 
for food and 
water hygiene 
•	 Discuss the list 
with your friend.
•	 What would 
you like to do 
to improve your 
personal hygiene.
 Health and Physical Education — Class IX
become potential carriers. Hence by washing hands, we 
can prevent diseases like diarrhoea, flu, skin and eye 
infections.
Food and water hygiene
•	 Drink potable water. If it does not appear clean, boil or 
filter and then consume it. 
•	 Eat only freshly prepared food or consume it within four 
hours of preparation. 
•	 Do not purchase and consume fruits and vegetables 
which have been cut and kept in the open for a long 
time. 
•	 Keep all food articles covered to prevent contamination 
by flies.
Environmental sanitation
•	 Use sanitary latrines; avoid open air defecation. 
•	 Throw waste in dustbins to avoid breeding of flies. 
•	 Clean the drains regularly.
•	 Regularly check the places where water is collected 
and has the possibilities of mosquito breeding. Spray 
insecticide to prevent breeding of mosquitoes. 
•	 Try to prevent contamination of drinking water (source of 
water should be away from source of garbage collection/
waste disposal site). The container of drinking water 
must be kept at a clean and safe place.
Vaccines 
Vaccines boost immunity and thus helps the body fight diseases. 
A large number of infectious diseases can be prevented by 
taking vaccines at an appropriate time, such as, diphtheria, 
pertussis, polio, tetanus, rabies, measles, chickenpox, typhoid, 
etc.
Treatment of diseases using medicines 
Medicines kill microbes and /or slow their growth. These are 
classified as anti-virals, anti-fungals, anti-protozoals and 
antibiotics according to the group of microbes they act upon.  
However, these medicines should be taken in the recommended 
dose and duration as advised by the doctor. One should avoid 
self-medication.
Isolation of patients with communicable diseases
Patients suffering from such diseases that are communicable 
should be kept in a clean environment isolated from others.
Education and awareness
It is important to make people aware about communicable 
diseases, their causes and modes of spread.  People should 
a ctIvIty 1.3
Have a round of your 
school. Find out 
the environmetnal 
sanitation.
Discuss with 
your classmates. 
If it is not good 
what will you do? 
Prepare a plan and 
implement.
a ctIvIty 1.4
Prepare an 
Immunisation 
chart. Put it in 
your classroom. 
Discuss with your 
classmates whether 
everyone has been 
vaccinated? If not, 
request them to 
consult a nearby 
health centre.
Health and Diseases 
also be made aware of their responsibilities towards control 
of communicable diseases, e.g. ensuring use of safe water, 
healthy food and proper management of garbage and waste 
disposal. 
1.4	 N oN –commuNicable 	D iseases
The	 non–communicable	 diseases	 may	 occur	 due	 to	 genetic	
and lifestyle factors. When these are caused by an unhealthy 
lifestyle, these diseases are also called lifestyle diseases. 
Risk	 factors	 of	 non–communicable	 diseases	 include	 lack	 of	
physical exercises, poor dietary habits, inadequate sleep, 
stress and habits like smoking, taking alcohol and tobacco 
chewing.
An	 arbitrary	 classification	 of	 non–communicable	 diseases	
can be:
Lifestyle diseases, such as diabetes, hypertension, heart 
diseases, stroke and cancer.
Mental health diseases like depression; and trauma.
Given below are the behavioural risk factors which can 
give way to manifestation of the physiological risk factors 
and ultimately lead to the diseases.  
1.4.1 High Blood Pressure or Hypertension 
Dietary factors  
All packaged and canned food items contain a very high level 
of sodium because of the presence of salt that is used as a 
preservative. If you are in the habit of adding table salt to your 
food you are consuming excess salt. Use of excess salt is linked 
with hypertension. Hence, consumption of excessive salt in 
daily food, packaged and canned foods need to be avoided. 
Sedentary lifestyle and lack of exercise  
You can put on excess weight, if you do not exercise daily. This 
excess weight and lack of exercise can lead to hypertension. 
Behavioural Risk 
Factors
Physiological Risk 
Factors
Disease  
Outcomes
•	 Unhealthy Diet
•	 Physical Inactivity
•	 Tobacco Use
•	 Alcohol Use
•	 Stress
•	 Blood Pressure
•	 Blood Glucose
•	 Cholesterol
•	 Weight Loss
•	 Heart Disease
•	 Stroke
•	 Diabetes
•	 Cancer
Source: National Programme for Prevention and Control of Cancer, Diabetes Cardiovascular Diseases and Stroke, A Guide 
for Health Workers, Ministry of Health and Family Welfare, GOI, New Delhi. For details on BMI, refer to chapter IV Activity 4.2
Fig. 1.1 : Risk Factors
b ox 1.1
•	 If one is obese one 
has a high chance 
of getting diabetes 
and hypertension. 
•	 Hypertension 
increases risk 
of getting heart 
attacks and strokes. 
•	 Diabetes mellitus 
affects all parts 
of the body like 
brain, eyes, heart, 
kidneys, blood 
vessels, muscles 
and nerves if 
precaution is not 
taken.