Bartter syndrome refers to a rare group of conditions that affect the kidneys. People with Bartter syndrome have a loss of potassium (hypokalemic alkalosis) and a rise in the hormone aldosterone.

See also: Aldosterone test

In some cases, Bartter syndrome may be genetic and the condition is present from before birth (congenital).

The condition is thought to be caused by a defect in the kidney's ability to reabsorb potassium. As a result, the kidneys remove too much potassium from the body. This is also known as potassium wasting. Unlike other forms of kidney disease, this condition does not cause high blood pressure.

This disease usually occurs in childhood. Symptoms include muscle cramping and weakness, constipation, increased frequency of urination, and growth failure.

The diagnosis of Bartter syndrome is usually made by finding low levels of potassium in the blood. The potassium level is usually less than 2.5 mEq/L. Other signs of this syndrome include:

• Normal blood pressure
• Low blood chloride
• Metabolic alkalosis
• High levels of the hormones renin and aldosterone in the blood
• High levels of potassium, calcium, and chloride in the urine

These same signs and symptoms can also occur in people who have taken too many diuretics or laxatives. Urine tests can be done to rule out these causes.

In Bartter syndrome, a biopsy of the kidney typically shows overgrowth of kidney cells called the juxtaglomerular apparatus. However, this is not found in all patients, especially in young children.