Potassium, Serum

Potassium, Serum

What it is

The Potassium, Serum test measures the level of potassium in the blood. Potassium is a key electrolyte that plays an essential role in regulating nerve signals, muscle contractions (including the heart), and maintaining fluid and acid-base balance. Abnormal serum potassium levels can be life-threatening, making this test an important part of routine electrolyte and kidney function evaluation.

Uses

This test is used to diagnose and monitor conditions that affect potassium balance, such as kidney disease, adrenal gland disorders, dehydration, and acid-base disturbances. It is also commonly ordered to monitor patients on diuretics, heart medications, or intravenous fluids, and in those with acute illnesses that may affect electrolyte balance.

Symptoms That May Lead to the Test

Doctors may recommend this test if you have:
– Muscle weakness, cramps, or twitching.
– Irregular heartbeats, palpitations, or chest pain.
– Fatigue, confusion, or numbness.
– Paralysis or difficulty breathing in severe cases.
– Abnormal results on other electrolyte or kidney tests.

Abnormal Results

High Serum Potassium (Hyperkalemia): May be caused by kidney failure, adrenal insufficiency (Addison’s disease), tissue breakdown (e.g., rhabdomyolysis, trauma), acidosis, or certain medications (ACE inhibitors, potassium-sparing diuretics). Severe hyperkalemia can cause dangerous heart rhythm disturbances.

Low Serum Potassium (Hypokalemia): May result from diuretic use, vomiting, diarrhea, hyperaldosteronism, malnutrition, or alkalosis. Severe hypokalemia can lead to muscle paralysis, respiratory problems, or life-threatening arrhythmias.

Results are usually interpreted with sodium and other electrolytes, kidney function tests, and clinical findings.

Risks

The test requires a standard blood draw. Risks are minimal and limited to mild pain, bruising, or dizziness at the puncture site. The laboratory analysis itself has no risks.