**How an Antacid Works**

An antacid is a medication that helps to relieve symptoms associated with excessive stomach acid, such as heartburn, indigestion, and acid reflux. It works by neutralizing the excess acid in the stomach, thereby providing relief from discomfort. Let's delve into the details of how an antacid works.

**1. Acid-Base Reaction:**
When you consume an antacid, it contains certain compounds that are alkaline in nature. These alkaline compounds act as bases and react with the excess stomach acid, which is predominantly hydrochloric acid (HCl). The reaction between the antacid and the acid results in the formation of water (H2O) and a salt, which is usually a combination of a metal cation and an anion.

**2. Neutralization of Excess Acid:**
The main mechanism behind antacids is neutralization. The alkaline nature of the antacid helps to raise the pH level of the stomach acid, which is normally highly acidic (pH 1 to 3). By increasing the pH level, the antacid counteracts the acidity of the stomach acid, bringing it closer to a neutral pH of 7. This neutralization process effectively reduces the irritating effects of excess acid on the lining of the stomach and esophagus, providing relief from symptoms.

**3. Protection of the Stomach Lining:**
Excessive stomach acid can lead to irritation and damage to the lining of the stomach and esophagus. Antacids not only neutralize the acid but also form a protective layer on the mucous membranes of the stomach and esophagus. This protective layer acts as a barrier, preventing further damage from the acid and promoting the healing process.

**4. Reduction of Pepsin Activity:**
Pepsin is an enzyme that is activated by stomach acid and plays a role in the digestion of proteins. However, when there is excessive acid in the stomach, pepsin can become overactive and contribute to tissue damage. Antacids help to reduce the activity of pepsin by neutralizing the acid, thereby preventing excessive digestion and minimizing the risk of tissue injury.

**5. Temporary Relief:**
It is important to note that antacids provide temporary relief from symptoms rather than addressing the underlying cause of excessive stomach acid production. In cases of chronic acid-related conditions, such as gastroesophageal reflux disease (GERD) or peptic ulcers, it is advisable to seek medical advice for appropriate diagnosis and treatment.

In summary, antacids work by neutralizing excess stomach acid, protecting the stomach lining, reducing pepsin activity, and providing temporary relief from symptoms associated with excessive acid production.

When hcl is produce in more amount then the base is taken which neutrilize it's effect.thus the base which neutrilize the acid is antacid.