Treatment for Kidney Stones

Kidney stone treatment depends on the size and type of stone, the underlying cause, the presence of any urinary infection, and whether the condition recurs. Stones 4 mm and smaller (less than 1/4 inch in diameter) pass without intervention in 90% of cases; those 5–7 mm do so in 50% of cases; and those larger than 7 mm rarely pass without a surgical procedure. Patients are advised to avoid becoming too sedentary, because physical activity, especially walking, can help move a stone.

Medications called alpha blockers have been shown to increase the spontaneous passage of kidney stones, especially smaller stones in the lower ureter near the bladder. These medications have the ability to relax the muscle tension inside the ureter. This relaxation serves to improve spontaneous stone passage rates by about 30%. Examples of alpha blocker medications include tamsulosin (Flomax®), alfuzosin (Uroxatral® ), terazosin (Hytrin® ), and doxazosin (Cardura® ). If you are trying to pass a stone, ask your physician about trying one of these medications.

If possible, the kidney stone is allowed to pass naturally and is collected for analysis. The patient is instructed to strain their urine to obtain the stone(s) for analysis. It is important to analyze the chemical composition of kidney stones to help determine how to prevent recurrent stone formation. The urine may be strained using an aquarium net or another device. Each voiding should be strained until the physician instructs the patient otherwise.

Dietary changes may be required and fluid intake should be increased. Patients with stones must increase their urinary output. Generally, 2000 cc of urine per day (slightly more than 1/2 gallon) is recommended and patients should drink enough water to produce this amount of urine daily. In some cases (e.g., some cystine stone formers), even higher levels of fluid intake are required.

Dietary calcium usually should not be severely restricted. Reducing calcium intake often causes problems with other minerals (e.g., oxalate) and may result in a higher risk for calcium stone disease.

Publication Review By: Stephen W. Leslie, M.D., F.A.C.S., Stanley J. Swierzewski, III, M.D.

Published: 10 Jun 1998

Last Modified: 02 Dec 2011