Kidney stones

Renal calculi; Nephrolithiasis; Stones - kidney; Calcium oxalate - stones; Cystine - stones; Struvite - stones; Uric acid - stones; Urinary lithiasis

A kidney stone is a solid mass made up of tiny crystals. One or more stones can be in the kidney or ureter at the same time.

Kidney stones

If you ever have severe pain in your belly or one side of your back that comes and goes suddenly, you may be passing a kidney stone. Let's talk about the painful condition of kidney stones. A kidney stone is a mass of tiny crystals in your kidney or urinary tract. Stones are quite common, and tend to run in families. They can form in weeks or months when your urine contains too much of certain substances. There are several kinds of kidney stones. Calcium stones are by far the most common kind. They often form in men between the ages of 20 to 30. Calcium can combine with other substances found in your food, like oxalate, phosphate, or carbonate, to form stones. Cystine stones can form in people who have cystinuria, a condition passed down through families in which stones are made from an amino acid called cystine. Struvite stones are found mostly in women who have urinary tract infections. These stones can grow very large and can block the kidney, ureter, or bladder. Uric acid stones are more common in men than in women. They can occur in people who have a history of gout or are going through chemotherapy. So, how do you know if you have kidney stones? Well, you may not have symptoms until the stone move down the ureter tubes through which urine empties into your bladder. When this happens, the stones can block the flow of urine out of your kidneys. The main symptom is severe sharp pain that starts suddenly, usually in your belly or one side of your back, and it may go away just as quickly. Other symptoms can include abnormal urine color, blood in your urine, fever, chills, nausea, and vomiting. So, what do you do about kidney stones? Well, your health care provider will perform a physical exam. You may need blood tests, kidney function tests, and tests that look for crystals in your urine. Several imaging tests, like a CT scan, can see stones or a blockage in your urinary tract. Treatment will depend on the type of stone you have, and how bad your symptoms are. Small kidney stones that are less than 5 mm in diameter will usually pass on their own. You should drink at least 6 to 8 glasses of water per day to produce a large enough amount of urine to help bring the stone out. Pain can be pretty bad when you pass a kidney stone, so your doctor may prescribe pain medicines to help as well as medications that will help the stone pass. Other medicines can decrease stone formation or help break down and remove the material that is causing you to make stones. You may need surgery if the stone is too large to pass, the stone is growing, or the stone is blocking your urine flow. Kidney stones are painful, but you can usually pass them without causing permanent harm. However, kidney stones often come back, so you and your doctor will need to work on finding the cause of your stone. Lastly, delaying treatment can lead to serious complications, so if you think that you have kidney stones see your doctor right away.

Kidney anatomy

The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and the stimulation of red blood cell production.

Kidney - blood and urine flow

This is the typical appearance of the blood vessels (vasculature) and urine flow pattern in the kidney. The blood vessels are shown in red and the urine flow pattern in yellow.

Kidney stones

Before we talk about how kidney stones are formed, take a moment to become familiar with the urinary tract. The urinary tract includes the kidneys, ureters, bladder, and urethra. Now let’s enlarge a kidney to get a closer view. Here’s a cross-section of the kidney. Urine flows from the outer cortex to the inner medulla. The renal pelvis is the funnel through which urine exits the kidney and enters the ureter. As urine passes through the kidneys, it can become very concentrated. When the urine becomes too concentrated, calcium, uric acid salts, and other chemicals dissolved in the urine can crystallize, forming a kidney stone, or renal calculus. Usually the calculus is the size of a small pebble. But ureters are very sensitive to being stretched, and when stones form and distend it, the stretching can be very painful. Often, people may not know they have kidney stones until they feel the painful symptoms resulting from a stone being stuck anywhere along the urinary tract. Fortunately, small stones typically pass out of the kidneys and through the ureters on their own, without causing any problems. However, stones can become more problematic when they block the flow of urine. Doctors call this one a staghorn kidney stone, and it is obstructing the entire kidney. Fortunately, these stones are the exception rather than the rule.

Nephrolithiasis

Kidney stones result when urine becomes too concentrated and substances in the urine crystalize to form stones. Symptoms arise when the stones begin to move down the ureter causing intense pain. Kidney stones may form in the pelvis or calyces of the kidney or in the ureter.

Lithotripsy procedure

Extracorporeal shock wave lithotripsy (ESWL) is a procedure used to shatter simple stones in the kidney or upper urinary tract. Ultrasonic waves are passed through the body until they strike the dense stones. Pulses of sonic waves pulverize the stones, which are then more easily passed through the ureter and out of the body in the urine.

Cystinuria

Cystinuria is a disorder characterized by cystine stones in the kidney, ureter, and bladder. A genetic abnormality results in abnormal transport of amino acids in the kidney. The high levels of the amino acid cystine in the urine lead to stone formation. While this disease only accounts for 1% to 2% of urinary tract stones in the general population, it is the most common cause among children.

Kidney pain

A kidney stone is a solid piece of material that forms in a kidney. Kidney stones may be the size of sand or gravel, as large as a pearl, or even larger. A stone can block the flow of urine and cause great pain.

Causes

Symptoms

Exams and Tests

Treatment

Outlook (Prognosis)

Possible Complications

When to Contact a Medical Professional

Prevention