Kidney stones

The problem of kidney and bladder stones is one of the oldest medical afflictions known to mankind. Today it is one of the most common diseases of the urinary system. It currently accounts for approximately one hospitalization in every thousand in the United States. The disease is more common in males, and generally strikes in the third decade of life. Stones are rare in children and in blacks. A hereditary factor has been reported, but environmental factors apparently play the predominant role, as family members living in the patient's household have stones more often than blood relatives who live elsewhere.

An English study revealed that spouses of calcium stone-formers excreted significantly more calcium in their urine than did spouses of nonstone-forming controls. The higher the calcium level excreted in the urine the higher the risk of stone formation.

As one would expect, a seasonal variation occurs in the number of causes of urinary stones; the highest incidence being in the hot, dry months of the year when the fluid part of the urine is lowest in relation to the solid parts such as calcium. The Southeastern states report the highest incidence, probably reflecting the longer periods of warm weather. New England reports the second highest incidence.

About half of all stones formed will pass spontaneously, the balance require surgical removal. Most kidney stones are calcium oxalate or calcium oxalate combined with calcium phosphate.

Symptoms of urinary stones vary. If the stone does not obstruct urine flow it may not produce symptoms and the first indication of urinary stone may be the expulsion of the stone though the urethra. Pain is by far the most common symptom, and may be provoked by slight physical disturbance such as automobile travel. Onset of the pain is generally sudden and severe. The patient may not be able to remain still for even an instant. The worst pain is usually confined to one side, but may become so severe it is difficult for the patient to say where it is most intense. It may radiate down from the back of the waist into the groin, sometimes extending into the external genitalia and thigh. There may be abdominal distention and nausea with repeated vomiting, rapid heart rate, elevated blood pressure, decreased urine output, bloody or cloudy urine and painful, frequent, or difficult urination.

Prevention and treatment

• Water drinking is not only the safest, but also the best treatment for urinary stones. It should be thought of first as it is imperative that the urine not become concentrated, encouraging stone formation. Patients should drink enough water to produce two to three quarts of urine daily. One quart of water should be taken during the night to maintain good urine flow at all times.
• An increase in urinary calcium is associated with an increased incidence of urinary stones. Use a low calcium diet, eliminating milk and all foods containing milk (cheese, yogurt, ice cream, etc.), fish, chocolate, cocoa, Ovaltine, antacids, collards, dandelion, mustard and turnip greens, and kale. Lactose in milk produces increased absorption of calcium.
• Daily vigorous outdoor exercise increases circulation to the urinary system. Stone formation is far more common in sedentary people. Lack of exercise may impair kidney drainage or alter calcium metabolism, producing skeletal decalcification and subsequent excretion of the extra calcium in the urine.
• Overnutrition may be a contributing factor in urinary stone formation. Use only two simple meals a day, the diet consisting principally of fruits, vegetables, and whole grains. At least one study suggests that a high intake of fruits and vegetables may actually protect against kidney stones. Avoid refined carbohydrates, high protein foods, vitamin and mineral supplements, and concentrated foods. Excessive vitamin D intake in the form of vitamin supplements increases calcium absorption thus encouraging stone formation.
• High intake of animal protein has been suggested as a factor favoring production of urinary stones. As much as possible, eliminate all high protein animal products (eggs, meats, cheese, etc.). Excessive dietary protein causes increased absorption as well as increased excretion of calcium.
• Bear in mind that a diet low in free fats will promote good blood circulation. Since a high sugar intake has been implicated as contributing to urinary stone formation, it is well to choose a diet low in or devoid of free sugars.
• Urinary stones are sometimes associated with gout. Persons with high uric acid levels should avoid foods high in oxalates. These include Ovaltine, cocoa, chocolate, coffee, tea, and cabbage.