Bartter's syndrome (BS) is a group of conditions involving enlargement of certain kidney cells, blood that is more alkaline than normal, high levels of potassium and chloride in the urine, loss of potassium from the kidneys (renal potassium wasting), dehydration, muscle weakness, muscle cramps, frequent urination, and growth deficiency, potentially resulting in dwarfism. It is thought to be caused by a defect in the body's ability to reabsorb potassium. Individuals with Bartter syndrome have a disturbed acid-base ratio (i.e., an accumulation of base or loss of acid) associated with a loss of potassium (hypokalemic alkalosis). Low amounts of potassium may result from overproduction of a certain hormone (aldosterone) that is essential in controlling blood pressure and regulating sodium and potassium levels (hyperaldosteronism). Even so, the blood pressure of people with Bartter syndrome is normal.