Symptoms
Kidney stones usually cause severe pain in their attempt to pass down the ureter on their way to the bladder. The pain is first felt in the side and thereafter in the groin and thighs. Other symptoms of kidney stones are a frequent desire to urinate, painful urination, scanty urination, nausea, vomiting, sweating, chills and shock. The patient may also pass blood with the urine. Sometimes large stones may remain in the kidneys without causing any trouble and these are known as ‘ silent ‘ stones.

Causes
The formation of stones in the kidneys is the result of defects in the general metabolism. They usually occur when the urine becomes highly concentrated due to heavy perspiration or insufficient intake of fluids. They are aggravated by a sedentary life style. The other causes are wrong diet, excess intake of acid-forming foods, white flour and sugar products, meat, tea, coffee, condiments and spices, rich foods and overeating. Lack of vitamin A and an excessive intake of vitamin D may also lead to formation of stones.

Types of Stones
Chemically, urinary stones are of two categories, namely, primary stones and secondary stones. Primary stones are ordinarily not due to infection and are formed in acidic urine. They usually result from alcoholoism, sedentary life, constipation and excessive intake of nitrogenous or purine-rich foods. Secondary stones are due to local infection and are formed in alkaline urine.
Most kidney stones are composed either of calcium oxalate or phosphate, the later being most common in the presence of infection. About ninety per cent of all stones contain calcium as the chief constituent. More than half of these are mixtures of calcium, ammonium and magnesium, phosphates and carbonates, while the remainder contain oxalate. Uric acid and cystine stones represent about four per cent and one percent, respectively, of the total incidence of stones.

Dietary Treatment
A majority of patients suffering from kidney stones can be treated successfully by proper dietary regulations. These regulations will also prevent a recurrence of the symptoms. Only a few cases require surgery.
The general precaution in dietary treatment of kidney stones is to avoid foods which irritate the kidneys, to control acidity or alkalinity of the urine and to ensure adequate intake of fluids to prevent the urine from becoming concentrated. The foods which are considered as irritants to the kidneys are alcoholic beverages, condiments, pickles, certain vegetables like cucumbers, radishes, tomatoes, spinach, rhubarb, watercress and those with a strong aroma such as asparagus, onions, beans, cabbage, and cauliflower , meat, gravies and carbonated waters.
In calcium phosphate stones, oversecretion of the parathyroid hormone causes loss of calcium from the bones resulting in a high blood level of calcium, with increased excretion of calcium in the urine. An abnormally high intake of milk, alkalis or vitamin D may also result in the formation of calcium phosphate stones.
For controlling the formation of calcium phosphate stones, a moderately low calcium and phosphorous diet should be taken. The intake of calcium and phosphates should be restricted to minimal levels consistent with maintaining nutritional adequacy. The maintenance level of calcium is 680 mg. and of phosphorus 1,000 mg. In this diet, milk should constitute the main source of calcium and curd or cottage cheese, lentils and groundnuts should form the main sources of phosphorus. Foods which should be avoided are whole wheat flour, Bengal gram, pea, soyabean, beet, spinach, cauliflower, turnips, carrots, almonds and coconuts.
When stones are composed of calcium and magnesium phosphates and carbonates, the diet should be so regulated as to maintain in acidic urine. In such a diet, only one pint of milk, two servings of fruits and two servings of vegetables ( 200 grams) should be taken. The vegetables may consist of asparagus, fresh green peas, squash, pumpkins, turnips, cauliflower, cabbage and tomatoes. For fruits, watermelons, grapes, peaches, pears, pineapples, papayas and guavas may be taken.
On the other hand , the urine should be kept alkaline if oxalate and uric acid stones are being formed. In this diet, fruits and vegetables should be liberally used and acid- forming foods should be kept to the minimum necessary for satisfactory nutrition. When the stones contain oxalate, foods with high oxalic acid contents should be avoided. These foods include almonds, beets, brinjals, brown bread, cabbages, cheeries, chocolates, french beans, potatoes, radishes and soyabeans.
Uric stones occur in patients who have an increased uric acid in the blood and increased uric acid excretion in the urine. Since uric acid is an end-product of purine metabolism, foods with a high purine content such as sweet breads, liver, and kidney should be avoided. The patient should take a low-protein diet, restricting protein to one gram per kg. of foods. A liberal intake of fluid upto 3,000 ml. or more daily is essential to prevent the production of urine at the concentration level where the salts precipitate out.
The patient should be given a large hot enema, followed by a hot bath with a temperature of 100 ^o F ., gradually increased to 112 o F. The head should be kept cold with cold application. Hot fomentation applied across the back in the region of the kidneys will relieve the pain. Certain yogasanas such as pavankuktasana, uttampadasana, bhujangasana, dhannurasana, ardhmatsyendrasana and halasana are highly beneficial as they stimulate the kidneys.

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