Kidney stones are small, solid masses that can form when salts or minerals become hardened crystals in the kidneys. Normally they are small enough to pass undetected. If the stones become large enough, they can become lodged in the ureter, the tube which carries urine from the kidney to the bladder. Kidney stones are four times more common in men than in women.
Kidney stones commonly fall into one of four categories: calcium stones, uric acid stones, cystine stones and struvite stones. Calcium and uric acid stones are more prevalent in men than women. Calcium stones are the most common, usually appearing between the ages of 20 and 30. They are likely to recur, often within five years of the first stone. Calcium can combine with other substances to form the stone. The most common substance is oxalate, which is found in many foods. Uric acid stones can occur with gout or chemotherapy.
Intense pain associated with kidney stones is known as renal colic. Severe pain may affect one or both sides of your back. Spasms of excruciating pain originating in the back below the ribs will radiate around to the abdomen and sometimes to the groin and genitals. Urine may become cloudy or bloody and may develop an unpleasant smell.You may feel sick or nauseous and may feel a frequent need to urinate. You may experience fever and chills.
Causes for kidney stones have not been proved to any degree of scientific certainty. Calcium stones are believed to be caused by problems in the breakdown and absorption of calcium and oxalate. Uric acid stones are created by excessive levels of uric acid in the body. Human body tissues, certain alcoholic drinks and some foods such as dried beans, peas and liver contain purines that break down into uric acid. Family history of kidney stones increases your risk factor as does eating a diet high in protein or not drinking enough water. Loss of a kidney, excessive use of laxatives and the use of certain medications may also lead to kidney stones.
Treatments vary with the type and size of the kidney stone. Stones smaller than 5mm (one-quarter-inch) can often be passed naturally with exercise and proper hydration. Medication may be recommended to help with any pain. Stones that do not pass naturally within two months are unlikely to do so. Extracorporeal shock wave lithotripsy (ESWL) is the most common way of treating these stones. Using X-rays or ultrasound to locate the stones, shock waves are passed through your skin to break the stones into smaller particles. The procedure is usually done under a local anesthetic. Percutaneous nephrolithotomy is a surgical procedure which employs an endoscope inserted through the kidney to remove large stones in or near the kidney.
Several factors can help prevent kidney stones or their recurrence. Drink lots of fluids particularly water and real lemon juice, not lemonade. Coffee and teas whether decaffeinated or not can be beneficial in moderation. Avoid colas with phosphoric acid. Avoid cranberry and apple juice as they contain oxalates. Low-salt and low-protein diets can help too. Magnesium and potassium may help reduce the chance of kidney stones particularly in men. Drug therapies can be employed if dietary measures are not successful.