Acidity is a condition of excess acid secretion that causes irritation and burning of the mucosal lining of the stomach. In Ayurveda this condition occurs due to an imbalance of the pitta dosha. This condition is a result of derangement of one of the sub-types of pitta dosha, Pachak. Pachak contributes to the digestive fire through the release of gastric juices. Excess secretion of hydrochloric acid in the stomach is described as Amlapitta, a disorder of the sour (acid) and liquid quality of pitta.
The main symptoms tend to appear between one to two hours after eating. This is the time when gastric juices have sufficiently processed the ingested food and the excess acid begins to irritate the mucosal membrane in the stomach. This results in feelings of restlessness, nausea (wanting to throw up) and actual vomiting; sour belching with an aftertaste of the already-eaten food; stiffness in the stomach; lack of appetite, indigestion or even constipation. If left untreated, the protective mucous lining may burn away allowing the strong digestive juices to form a sore in the stomach wall.
Since it is the pitta dosha that causes acidity you should avoid excessively sour or spicy foods and liquids, fermented foods, white flour products and white sugar products. Avoid tea, coffee, smoking and alcohol. Excessive exposure to sun and heat should also be avoided. Eat at regular intervals and make sure you get adequate sleep. Curd should be strictly avoided at night.
You should eat foods that are light, fresh and easy to digest and preferably alkaline. Barley, whole wheat, basmati rice, steamed dark leafy greens, pomegranate or cranberry juice should be a major part of your diet. Aloe vera juice taken a half hour before or after meals can help to soothe the entire gastro-intestinal tract. Tea made from coriander, cumin, and fennel seed is cooling to the system and is an effective digestive aid. Chew a small piece of jaggery after lunch and dinner. Repeat until acidity subsides. Otherwise eat raw almonds, an alkaline-producing food that can balance your pH level. French volcanic clays when eaten in right proportion have miraculous effects on acidity. Chamomile, mint or fenugreek tea may help reduce acid reflux symptoms too.
Mix together equal parts of powdered fennel, licorice root, basil leaves and coriander seeds. Have ½ teaspoon of this mixture with ½ teaspoon of powdered rock candy (or unrefined sugar) 15 minutes before lunch and dinner.
Practising Vajrasana for 5-10 minutes after every meal will help you a lot.