Kidney Stones - Symptoms, Causes, and Treatment

What are kidney stones?

Kidney stones, or renal calculi, are solid masses made of crystals. Kidney stones usually originate in your kidneys. However, they can develop anywhere along your urinary tract, which consists of these parts:

kidneys
ureters
bladder
urethra

Kidney stones are one of the most painful medical conditions. The causes of kidney stones vary according to the type of stone.

Types of kidney stones

Not all kidney stones are made up of the same crystals. The different types of kidney stones include:

Calcium

Calcium stones are the most common. They’re often made of calcium oxalate (though they can consist of calcium phosphate or maleate). Eating fewer oxalate-rich foods can reduce your risk of developing this type of stone. High-oxalate foods include:

potato chips
peanuts
chocolate
beets
spinach

However, even though some kidney stones are made of calcium, getting enough calcium in your diet can prevent stones from forming.

Uric acid

This type of kidney stone is more common in men than in women. They can occur in people with gout or those going through chemotherapy.

This type of stone develops when urine is too acidic. A diet rich in purines can increase urine’s acidic level. Purine is a colorless substance in animal proteins, such as fish, shellfish, and meats.

Struvite

This type of stone is found mostly in women with urinary tract infections (UTIs). These stones can be large and cause urinary obstruction. They result from a kidney infection. Treating an underlying infection can prevent the development of struvite stones.

Cystine

Cystine stones are rare. They occur in both men and women who have the genetic disorder cystinuria. With this type of stone, cystine — an acid that occurs naturally in the body — leaks from the kidneys into the urine.

Risk factors for kidney stones

The greatest risk factor for kidney stones is making less than 1 liter of urine per day. This is why kidney stones are common in premature infants who have kidney problems. However, kidney stones are most likely to occur in people between the ages of 20 and 50.

Different factors can increase your risk of developing a stone. In the United States, white people are more likely to have kidney stones than black people.

Sex also plays a role. More men than women develop kidney stones, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

A history of kidney stones can increase your risk. So does a family history of kidney stones.

Other risk factors include:

dehydration
obesity
a diet with high levels of protein, salt, or glucose
hyperparathyroid condition
gastric bypass surgery
inflammatory bowel diseases that increase calcium absorption
taking medications such as triamterene diuretics, antiseizure drugs, and calcium-based

Kidney Stones - Symptoms, Causes, and Treatment