✍️ Edited by Farhan Ahmed, Editor, MedTestBD · Last updated: August 2026
What Is a Serum Potassium Test?
A Serum Potassium test measures the amount of potassium in the liquid part of your blood. Potassium is an electrolyte, a mineral that carries a small electrical charge and helps your nerves fire, your muscles contract, and above all keeps your heartbeat steady. Your body works hard to hold potassium within a narrow range, so even small shifts up or down can matter. The test is a simple blood draw and is often done together with sodium and other electrolytes as part of a serum electrolyte panel.
Why Is a Serum Potassium Test Done?
Doctors order this test for many reasons. It is used to check kidney function, since the kidneys control how much potassium stays in the body. It helps monitor people taking medicines that affect potassium, such as diuretics (water pills) or blood pressure drugs. It is also used when someone has symptoms like muscle weakness, cramps, an irregular heartbeat, or extreme tiredness. People with diabetes, heart disease, or long-term kidney problems often have this test repeated to catch changes early.
Normal Serum Potassium Levels
For most adults, a normal serum potassium level falls between 3.5 and 5.0 milliequivalents per litre (mEq/L), according to MedlinePlus. A level below 3.5 is called hypokalaemia (low potassium) and can cause weakness, cramps, and heart rhythm problems. A level above 5.0 is called hyperkalaemia (high potassium) and is potentially serious because it can disturb the heartbeat. Ranges can vary slightly between labs, and a very high or low reading is sometimes caused by the blood sample itself, so your doctor may repeat the test to confirm before acting on it.
How to Prepare for the Serum Potassium Test
- No fasting is usually required, though your doctor may ask you to fast if potassium is being checked alongside glucose or a lipid panel.
- Tell the lab about all medicines and supplements you take, especially potassium supplements, diuretics, or blood pressure medicines, as these directly affect the result.
- Avoid clenching or pumping your fist repeatedly during the blood draw, since this can falsely raise the reading.
- Continue your normal diet unless told otherwise.
Serum Potassium Test Price in Bangladesh
The Serum Potassium test price in Bangladesh generally ranges from about BDT 225 to BDT 450, depending on the diagnostic centre and whether it is offered at a discounted rate. Many labs include potassium within a full electrolyte panel, which can change the price. Compare the latest Serum Potassium test prices on MedTestBD →
Normal ranges cited on this page are based on MedlinePlus and WHO guidance. Prices are collected from public sources and may change — confirm with the facility before visiting. This information is for general reference only and is not medical advice. Always consult a qualified physician.
