Search the A to Z Guide

Kidney stones have become more common in children and teens over the past 20 years. They can occur in children of any age, even premature infants, but most stones occur in teens. Kidney stones happen when minerals and other substances normally found in urine join together to form a hard stone in...

How many kidneys do I have? Most people have two kidneys. Kidneys are inside the body. They are about the size of your fist. Where are your kidneys? Kidneys are in your lower back. What do kidneys do? Kidneys are busy! They are like washing machines for the blood in the body.  The kidneys...

Medullary sponge kidney (MSK) is a congenital disorder, meaning it is present at birth. MSK occurs when small cysts (sacs) form either on tiny tubes within the kidney (known as tubules) or the collecting ducts (a channel where urine is collected for removal). These cysts can reduce the outward flow...

What is an ectopic kidney? An ectopic kidney is a kidney that is out of place.  An ectopic kidney is caused by a birth defect. What causes an ectopic kidney? An ectopic kidney happens while a baby is growing in the womb.  Normally, the kidneys form a kidney bud within the pelvis (hip...

Normally, kidneys are about the size of a fist or 10 to 12 cm (about 5 inches). Kidney atrophy means that the kidney is smaller than normal. This can happen for two basic reasons. The first is that part of the kidney does not develop from birth (called a congenital problem) making a small kidney....

Kidneys perform crucial functions that affect all parts of the body and are involved in complex operations that keep the rest of the body in balance. When the kidneys are damaged by disease, other organs are affected. Kidney problems can range from a minor urinary tract infection to progressive...

33% of American adults are at risk for kidney disease. Yes, one in three people. If you are Black or African American, Hispanic or Latino, Asian American, Pacific Islander, American Indian, or Alaska Native, or Native Hawaiian or Other Pacific Islander, heritage you may be at an increased risk...