Acidity

Introduction
Cause and Pathogenesis
Symptoms and Signs
Investigations and Diagnosis
Treatment and Prognosis
Prevention

Acidity refers to a set of symptoms caused by an imbalance between the acid secreting mechanism of the stomach and proximal intestine and the protective mechanisms that ensure their safety. The stomach normally secretes acid that is essential in the digestive process. This acid helps in breaking down the food during digestion. When there is excess production of acid by the gastric glands of the stomach, it results in the condition known as acidity. However, there are certain types of ulcers where acid secretion is either normal or even low. Acidity is responsible for symptoms like dyspepsia, heartburn and the formation of ulcers (erosion of the lining of the stomach or intestines). Acidity tends to have a much higher incidence in highly emotional and nervous individuals. It is also more common in the developed and industrialised nations, though a recent increase in incidence has also occurred in the developing countries. Consumption of Alcohol, highly spicy foodstuffs, non-vegetarian diets, and Non Steroidal Anti-Inflammatory Drugs (NSAID's) also predispose to gastric acidity.

The stomach, intestines, and digestive glands secrete hydrochloric acid and various enzymes, including pepsin that break down and digest food. The stomach must also be protected from the same acid and enzymes, or it too can be attacked by the gastric juices. The acid may enter the lower part of the Oesophagus (Gastro-Oesophageal Reflux), due to some weakness in the normal sphincter mechanism that prevents such reflux. This causes heartburn. It commonly occurs after meals and is brought on by excess intra-abdominal pressure like lifting weights or straining.

Ulcers also occur as a result of over secretion of acid. This may happen when there is an imbalance between the digestive juices used by the stomach to break down food and the various factors that protect the lining of the stomach and duodenum (the part of the small intestine that adjoins the stomach). A peptic ulcer is a raw area in the lining of the upper part of the small intestine (duodenal ulcer) or the stomach (gastric ulcer), whose protective mucosal lining has been eroded away by the gastric juices. Duodenal ulcers are three times more common than gastric ulcers. Hydrochloric acid, secreted in the stomach, is one of the factors in the development of ulcers, but is not solely responsible. Acid production in patients with duodenal ulcers tends to be higher than normal, while in those with stomach or gastric ulcers, it is usually normal or lower.

Excessively large amounts of acid secretion occur in certain situations, such as in a condition known as Zollinger-Ellison Syndrome, in which large amounts of secretion are stimulated by tumours located in the pancreas or duodenum. Pepsin is an enzyme that breaks down proteins. Pepsin and hydrochloric acid cause damage to the stomach or duodenum if the stomach's protective system is altered or damaged. The mucous layer, which coats the stomach and duodenum, forms the first line of defence against acid and pepsin. The body also secretes bicarbonate into the mucous layer, which neutralises the acid. The defence system also consists of hormone-like substances known as prostaglandins, which help to keep the blood vessels in the stomach dilated, ensuring adequate blood flow. Lack of adequate blood flow to the stomach contributes to ulcers. Prostaglandins are also believed to stimulate bicarbonate and mucous production, which help protect the stomach. If any of these defence mechanisms are deficient, acid and pepsin can attack the stomach lining causing an ulcer.

Dyspepsia and heartburn are often the main symptoms of acidity. Heartburn is characterised by a deeply placed, burning pain in the chest behind the sternum (breast-bone). It occurs after meals and is brought on by excess intra-abdominal pressure like lifting weights or straining. It can also occur at night on lying down and is relieved when the individual sits up. The pain is very closely related to posture. Regurgitation of the gastric contents may also occur. The symptoms of ulcers are mainly pain that can be either localised or diffused. Sometimes it radiates to the back or to the chest.

The most common symptom is dyspepsia, a burning or aching pain in the upper abdomen sometimes described as a "stabbing feeling penetrating through the width of the gut". Rarely, there is no pain at all, but only a feeling of indigestion or nausea. Eating a meal usually relieves the pain in duodenal ulcer, but in a gastric ulcer there may be no change, or the pain may become worse. Peptic ulcer disease can sometimes occur without symptoms. Symptoms may also arise when there is no ulcer present, which is known as non-ulcer dyspepsia.

The clinical symptoms and history are very important aspects of diagnosis. Any present and past drug use, especially chronic use of NSAIDs, a history of family members with ulcers, alcohol consumption and smoking, stress assessment and analysis are very useful in determining the cause of the condition. A trial with acid-blocking medication is given with a four-week course of acid-suppressing drugs. In such cases, the symptoms may subside. If symptoms persist, then further testing is needed. Upper Gastrointestinal Endoscopy is done to detect the presence of ulcers. If Zollinger-Ellison Syndrome is suspected, blood levels of gastrin should be measured. Barium Meal studies are also useful as these may show inflammation, active ulcer craters, or deformities and scarring due to ulcers. If an ulcer is present, a precautionary biopsy of the ulcer is usually taken to rule out malignancy as it is not uncommon for a malignancy to manifest as an ulcer.

Identifying and avoiding the causative factors are essential in the treatment of acidity. A suitable diet must be strictly followed avoiding spicy, salty and acidic foods. Smoking and alcohol consumption must be stopped. Those with highly nervous and emotional disposition and those involved in high-stress jobs must be encouraged to take lifestyle modifying measures. Antacids provide immediate relief of symptoms by neutralising the excess acid secreted. A group of drugs called H2 Receptor Blockers cause the stomach to produce less acid by blocking histamine receptors (example: Drugs like Cimetidine , Ranitidine, Famotidine or Nizatidine). Another group of drugs called the Proton Pump Inhibitors, which selectively disable a mechanism in acid-making cells thus stopping acid production are more powerful and include Omeprazole and Lansoprazole. If ulcers have developed, they must be diagnosed rapidly and treated to prevent complications like perforations. Long term therapy lasting for weeks may be required to produce complete healing. Surgical methods of reducing the acid secretion like Vagotomy are being used with decreasing frequency.

Prevention mainly consists of avoiding the known causative factors like alcohol consumption, spicy foods, drugs like NSAID's, steroids etc. Patients with highly nervous and emotional disposition and those involved in high-stress jobs must be given psychological treatment. Avoiding non-vegetarian diets is also useful in minimising symptoms of acidity.