Potassium concentration in serum or plasma

Why Is This Test Done?

Your doctor may order this test to check for low (hypokalemia) or high (hyperkalemia) potassium levels, which can cause symptoms like muscle weakness, irregular heartbeat, or fatigue. It’s often done when you have symptoms, are taking certain medications, or have conditions like kidney disease or heart problems.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for a few hours before the test if it’s part of a larger blood panel. Bring any medications you’re currently taking to your appointment.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood sample is then sent to a lab for analysis.

What Are Common Results?

Results are typically reported in milliequivalents per liter (mEq/L). While specific reference ranges vary by lab, low potassium levels may indicate dehydration, certain medications, or metabolic issues, while high levels can signal kidney problems or excessive potassium intake.