Common cold and pneumonia are both respiratory illnesses, but they differ in various aspects. Let's explore the differences between the two:

Cause:
- Common Cold: Common cold is caused by a viral infection, primarily by rhinoviruses. Other viruses such as coronaviruses, adenoviruses, and respiratory syncytial virus (RSV) can also lead to a common cold.
- Pneumonia: Pneumonia can be caused by various pathogens including bacteria, viruses, fungi, and parasites. The most common cause of pneumonia is the bacterium Streptococcus pneumoniae.

Symptoms:
- Common Cold: Symptoms of a common cold typically include a runny or stuffy nose, sneezing, sore throat, cough, mild headache, and mild body aches. Fever is usually absent or low-grade.
- Pneumonia: Pneumonia symptoms can be more severe than those of a common cold. They may include high fever, chills, cough with phlegm or pus, shortness of breath, chest pain, rapid breathing, fatigue, and confusion in older adults.

Duration:
- Common Cold: A common cold usually lasts for about 7-10 days, with symptoms gradually improving over time.
- Pneumonia: Pneumonia can have a longer duration, ranging from a few days to several weeks, depending on the severity of the infection and the individual's overall health.

Severity:
- Common Cold: A common cold is generally a mild illness that does not lead to serious complications in healthy individuals.
- Pneumonia: Pneumonia can be a severe and life-threatening condition, especially in older adults, young children, and individuals with weakened immune systems. It can lead to complications such as respiratory failure, sepsis, and organ damage.

Diagnosis and Treatment:
- Common Cold: Diagnosing a common cold is usually based on symptoms and does not require specific medical tests. Treatment includes rest, staying hydrated, over-the-counter medications for symptom relief, and home remedies.
- Pneumonia: Diagnosis of pneumonia may involve physical examination, chest X-ray, blood tests, and sputum culture. Treatment depends on the cause of pneumonia and may involve antibiotics (for bacterial pneumonia), antiviral medication (for viral pneumonia), rest, fluids, and sometimes hospitalization.

In conclusion, while both common cold and pneumonia are respiratory illnesses, they differ in terms of causative agents, symptoms, duration, severity, and treatment. It is important to differentiate between the two to ensure appropriate management and prevent complications. If you suspect pneumonia or experience persistent and severe symptoms, it is advisable to consult a healthcare professional for proper evaluation and guidance.