Acidity is a term used for a set of symptoms caused by excess production of acid by the gastric glands of the stomach.The stomach normally secretes hydrochloric acid which is required for the breakdown and digestion of food we eat.reatment. Usually, acidity is treated with the help of antacids which contain either magnesium or calcium or aluminium containing compounds. These antacids neutralise the excess acid in the stomach thus providing relief from the symptoms.