lowpotassium

Low potassium, or hypokalemia, is a lower-than-normal serum potassium level. In adults, normal potassium is about 3.5–5.0 mEq/L; hypokalemia is typically defined as below 3.5. Potassium is essential for muscle and nerve function and for maintaining heart rhythm.

Common causes include gastrointestinal losses (vomiting, diarrhea), urinary losses from diuretic use and certain kidney disorders, insufficient dietary intake, or shifts of potassium into cells caused by insulin or alkalosis. Magnesium deficiency, alcohol use, and some medications can worsen or precipitate hypokalemia. Risk groups include people with kidney disease, those taking diuretics, and those with chronic diarrhea or vomiting.

Symptoms range from none in mild cases to muscle weakness, cramps, fatigue, constipation, and heart rhythm disturbances in more severe cases. Sudden severe hypokalemia can cause paralysis or life-threatening arrhythmias.

Diagnosis is based on a blood test showing potassium below the normal range, and may include an ECG to detect heart effects. Additional tests may assess urinary potassium, acid-base status, and magnesium level to identify the cause.

Treatment depends on severity and cause. Mild symptoms may be treated with oral potassium supplements and dietary changes. Moderate to severe cases require potassium replacement, often by intravenous infusion with careful monitoring to avoid overcorrection. Correcting magnesium deficiency when present improves potassium restoration. Ongoing management focuses on correcting underlying causes and preventing recurrence.

Prevention includes monitoring high-risk individuals, adjusting diuretic therapy, and ensuring adequate dietary potassium. Prompt treatment usually yields good outcomes; severe hypokalemia can be dangerous.

See also: potassium, electrolyte disorders.