KIDNEY STONES (RENAL CALCULI)

Valuable information for over 200 common illnesses

General Illness Information

Medical Term:

Kidney Stones (Renal Calculi)

Common Name:

None Specified

Description:

Small solid particles (stones) that form in the kidney and sometimes travel down to the urethra (tube that connects kidney to urinary bladder). About 1 in 1000 adults is hospitalized annually in the USA because of urinary calculi, which are also found in about 1% of all autopsies.

Causes:

Almost 95% of all kidney stones are calcium stones. They occur when there is too much calcium in the urine.

A second type of kidney stone is made of uric acid. These stones are much less common than calcium stones. Uric acid stones occur because you have too much uric acid in your urine. They might occur if you have become dehydrated; for example, during strenuous exercise on a hot day or perhaps during an illness. Uric acid stones are common in people who have gout, a disease that causes high uric acid levels in the blood.

A third type, struvite stones, are not quite so well understood. It is thought that these stones form as a result of an interaction between protein-breakdown products and infection-causing bacteria in the urine.

Finally, a rare type of kidney stone is a cystine stone. It occurs if you have the genetic disease called cystinuria. This disease results from a birth defect that causes the kidney to allow too much cystine into the urine. This type of stone formation is almost always diagnosed during childhood.

Prevention:

If you do not have any underlying health problems, the most important thing is to drink plenty of water daily. The goal should be to urinate from 2 to 4 liters per day. Make sure you avoid getting dehydrated.

There are no specific dietary recommendations until a stone from your system has been analyzed. After analysis your diet can be evaluated and any changes recommended.

Signs & Symptoms

	Episodes of severe, colicky (intermittent) pain every few minutes. The pain usually appears first in the back, just below the ribs. Over several hours or days, the pain follows the stone's course through the ureter toward the groin. Pain stops when the stone is passed in the urine.
	Blood in urine. Urine may appear cloudy or dark.
	Episodes of nausea associated with renal colic.
	Some people have no symptoms, until they pass gravel-like stones in the urine.
	Kidney or urinary infection may be caused by the stone. In these cases, symptoms may be caused by the infection. These are fever, chills and backache.

Risk Factors

	Decreased urine volume due to dehydration.
	Improper diet (too much calcium).
	Hyperparathyroidism, which causes high blood and urinary calcium levels.
	Family history of kidney stones.
	Gout, which is caused by high uric acid levels in the blood, and gives rise to uric acid stones.
	Excess alcohol consumption.
	Bed confinement for any reason.
	Geographical living area (southeastern U.S.).

Diagnosis & Treatment

Diagnostic tests may include urinalysis and urine culture, X-ray of the abdomen, kidney ultrasound, CT scan, intravenous urography.
General Measures:
	Strain all urine through filter paper or gauze to detect passage of the stone; or urinate into a glass jar, look for and recover stone and discard the urine. Take stone to the doctor for composition analysis.
	Small solitary stone, uncomplicated by obstruction of infection may need no specific treatment.
	Treatment will be required to remove larger stones, if they don't pass spontaneously, and are causing complications, infection or severe pain. Options include chemical dissolution, endoscopic stone extraction, percutaneous nephrolithotomy, extracorporeal shock wave lithotripsy, and rarely, open surgery. A new method is being used for higher or larger stones. This is by means of a ureteroscope, which is an operating telescope, inserted through the bladder.
	Stones due to excess calcium in the body maybe caused by parathyroid gland tumor, and require surgical removal of abnormal parathyroid tissue.

Medications:
	Very strong pain killers are required for renal colic.
	Depending on the type of stone (calcium containing, cystine stones, uric acid or other composition), medication may be prescribed that will stop the growth of existing stones or new stones. This often involves a prolonged program and your compliance is important.

Activity:
During a kidney-stone episode, stay active. Don't go to bed. Activity may help the stone pass. However, avoid situations which can endanger you or others if you have renal colic.

Diet:
	There are no specific dietary recommendations until a stone from your system has been analyzed. After analysis your diet can be evaluated and any changes recommended.
	If the stone proves to be calcium or phosphorus, avoid products made of milk, chocolate and nuts.
	If the stone is a phosphate, an acid-ash diet will keep the urine slightly acid.
	For all types of stones, drink at least 13 glasses of fluid daily. Most of the fluids should be purified water.
	In cases of uric acid stones, intake of meat, fish, and poultry should be reduced

Possible Complications :
	Urinary-tract infection.
	Damage to the kidney, necessitating surgical removal.
	Recurrence of stones.

Prognosis

Prognosis is excellent with treatment. Underlying causes must be treated effectively.

Other

'Nothing Specified'.