Description: A concretion in the kidney usually made up of calcium oxalate, calcium phosphate or uric acid; also known as renal calculi.
Persons most commonly affected: Adults of both sexes aged over 30 years but more common in men than women.
Organ or part of body involved: Kidneys and ureters.
Symptoms and indications: Severe stabbing pain in the back that comes and goes, nausea, and there may be slight amounts of blood in the urine. A kidney stone that does not pass on out can block the urinary tract. This blockage will probably cause pain initially. But if medical attention is not received to identify the cause of the pain and remove the blockage, the pain is likely to gradually go away over a few days time. This lack of pain may cause the sufferer to think the crisis has passed when, in fact, the kidney which has been blocked by the stone has shut down. If left untreated in just a few days this shut down can lead to permanent loss of function in that kidney. A kidney stone can even rupture the collection system of the kidney.
Causes and risk factors: There are various causes or factors that favour the formation of kidney stones. These include a high level of calcium in the urine, which may come from drinking large quantities of milk and eating foods that are rich in vitamin D, which helps the body to absorb calcium, a change in the acidity or alkalinity of the urine, concentration of the urine, which may occur if too little fluid is drunk or if sweating is excessive as in hot climates, a diet of fruits and vegetables high in oxalate (a by product of metabolism), urinary infection, or possibly, just leading a sedentary (low physical activity) life-style. Also gout, a family tendency, a diet deficient in vitamin A and an overactive parathyroid gland are all factors that may lead to the formation of stones.
Prevention: The easiest step to take is to increase hydration. This applies to sufferers of all types of kidney stones. Drinking very large amounts of water/fluids, particularly at night, reduces urine concentration so that stones cannot form. Surplus fluid can also flush the system of any small stones. High calcium in urine can be caused by too much salt in a person's diet. Salt causes excretion of larger amounts of calcium and thus increases calcium in the urine. Increasing a person's intake of water will reduce the relative concentration of calcium in the urine and thus reduce the risk of crystal formation and kidney stone formation. Additionally, persons prone to the most common type of kidney stones (calcium oxalate) may find it advisable to cut back on foods with high oxalate levels such as apples, asparagus, beer, beets, various berries, black pepper, broccoli, cheese, chocolate, cocoa, coffee, cola drinks, collards, figs, grapes, ice cream, milk, oranges, parsley, peanut butter, pineapples, spinach, rhubarb, tea, turnips, vitamin C, and yogurt to help prevent future stone formation.