The most usual is that the gastric glands are pouring out an insufficient amount of secretion; almost always there is a deficiency of hydrochloric acid. In some cases in which the food has irritated and inflamed the stomach there may be a sufficient secretion of this acid, but an inflamed stomach throws off more mucus and the extra quantity of mucus neutralizes the hydrochloric acid. When the acid is deficient or absent, the proteins are not well digested and the food may ferment; bacteria may produce putrefactive changes and the formation of gas. The gas interferes with the movement of the diaphragm, pressing it against the heart, causing pain and even palpitation. Indigestion is usually accompanied by constipation, or by irregular action of the intestines. Plenty of fresh air, and exercise, directed definitely to muscles and nerves of the stomach, that it may be strengthened by a better blood supply, as well as exercises and deep breathing to build up the general health, should be systematically followed. Easily digested food, well masticated, and regular meals served daintily, will gradually regulate digestion. Food should not be of too great a variety at one meal. It must be simple and well prepared; when nerves and muscles are weak it should be served less in quantity but more frequently. Sometimes light food every hour or every two hours is best. Cheerful constructive thoughts are the very best of medicine for digestive derangements. A glass of cold water from one-half to an hour before the meal will cleanse the stomach by washing out the mucus and will promote the secretion of saliva and the gastric juices. The intelligent medical treatment of stomach difficulties is aided by a chemical analysis of the stomach contents. If the stomach is not secreting normal proportions of pepsin or hydrochloric acid, the deficiency of either can be determined. Such chemical analysis will alone determine what elements are lacking. Permanent relief must lie in gaining a good circulation of blood through the entire body and through the stomach, that it may be strengthened and thus enabled to secrete these elements in proper proportions. [Sidenote: Nervous Indigestion] This is due to the general depleted condition of the nerves. In such cases the entire nervous system should be regulated through exercise, breathing, rest, and a change of thought. Physicians usually recommend change of scene to cause a change of thought. The diet should be light and laxative, and low in protein. Cream soup, bread and milk, malted milk, buttermilk, cream, fruits, crackers and milk, custards, egg lemonade, and gruels, furnish easily digested food. Tea, coffee, much meat, fried food, highly spiced food, pastry, candies, pickles, alcohol, and tobacco should be avoided.