Kidney Stones

Kidney Stones

Kidney stones, also known as renal calculi or nephrolithiasis, are hard deposits made of minerals and salts that form inside the kidneys. The process of stone formation is called urolithiasis, renal lithiasis, or nephrolithiasis. Kidney stones can affect any part of the urinary tract — from the kidneys to the bladder. Often, stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together.

Causes

The formation of kidney stones is influenced by several factors. These include dehydration, certain diets, obesity, certain supplements and medications, and certain medical conditions such as gout and hyperparathyroidism. Dietary factors that increase the risk include high intakes of animal protein, sodium, refined sugars, fructose, and high fructose corn syrup, and insufficient intake of water and dietary calcium.

Symptoms

Kidney stone symptoms may not occur until the stone begins to move down the ureters. This severe pain is called renal colic. Symptoms of renal colic can include pain in the side and back, below the ribs, pain that radiates to the lower abdomen and groin, pain that comes in waves and fluctuates in intensity, pain on urination, pink, red or brown urine, cloudy or foul-smelling urine, nausea, vomiting, persistent urge to urinate, urinating more often than usual, and fever and chills if an infection is present.

Diagnosis

Diagnosis of kidney stones is best accomplished using an imaging test such as an ultrasound or a non-contrast CT scan. A CT scan is more often used because it is more accurate and can diagnose almost all types of kidney stones.

Treatment

Treatment for kidney stones varies depending on the size of the stone and its location. Small stones with minimal symptoms can often be managed with pain relief medications and increased water intake, while larger stones may require more invasive treatments. These treatments can include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, or percutaneous nephrolithotomy. ESWL uses shock waves to break a large stone into smaller pieces that can pass through the urinary tract more easily.

Prevention

Prevention of kidney stones involves a combination of lifestyle changes and dietary adjustments. Recommendations include drinking enough fluids, particularly water, reducing salt and animal protein intake, and consuming foods rich in dietary calcium. Medical therapy may include medications to control the level of minerals and acid in the urine.

Epidemiology

Kidney stones are a common health issue worldwide. They affect about 1 in 11 people in the United States. The prevalence of kidney stones in the U.S. has been increasing over the past 30 years, and they are more common in men than in women. Most people who experience kidney stones do so between the ages of 20 and 50.