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A potassium test measures how much potassium is in the urine. Potassium is both an electrolyte and a mineral. It helps balance the amounts of water and electrolytes in the body. (Water is the amount of fluid inside and outside the body's cells.) It is also important in how nerves and muscles work.
Potassium levels often change with sodium levels. When sodium levels go up, potassium levels go down. When sodium levels go down, potassium levels go up. These levels are also affected by a hormone called aldosterone. This hormone is made by the adrenal glands.
Potassium levels can be affected by how the kidneys are working, the blood pH, and the amount of potassium you eat. The hormone levels in your body, severe vomiting, and taking certain medicines such as diuretics and potassium supplements can also affect the levels. Certain cancer treatments that destroy cancer cells can also raise potassium levels.
Many foods are rich in potassium. Some examples are potatoes, bananas, prunes, orange juice, and winter squash. A balanced diet has enough potassium for the body's needs. But if your levels get low, it can take some time for your body to start holding on to potassium.
A potassium level that is too high or too low can be serious. Abnormal levels may cause symptoms such as muscle cramps or weakness, nausea, diarrhea, or frequent urination. Other symptoms may include dehydration, low blood pressure, confusion, irritability, paralysis, and changes in heart rhythm.
A urine test to check potassium levels is done to look for the cause of a low or high blood potassium test result.
You do not need to do anything special to prepare for this test.
Talk to your doctor if you have any concerns about the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form .
Urine potassium can be checked in a single urine sample. But it is more often measured in a 24-hour urine sample.
It is not painful to collect a one-time or 24-hour urine sample.
Collecting a one-time or 24-hour urine sample does not cause problems.
A test for potassium in the urine is a 24-hour test or a one-time (spot) test. It checks how much potassium is in the urine. Potassium is both an electrolyte and a mineral.
These numbers are just a guide. The range for "normal" varies from lab to lab. Your lab report should show what range your lab uses for "normal." Also, your doctor will evaluate your results based on your health and other factors. So a number that is outside the normal range here may still be normal for you.
Results are ready in 1 day.
25–125 milliequivalents (mEq) per day (24 hours) or 25–125 millimoles (mmol) per day (24 hours)
10–60 mEq per day (24 hours) or 10–60 mmol per day (24 hours)
Many conditions can affect potassium levels. Your doctor will talk with you about any abnormal results as they relate to your symptoms and past health.
You may not be able to have the test, or the results may not be helpful, if:
CitationsFischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Other Works ConsultedChernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Current as of: September 23, 2020
Author: Healthwise StaffMedical Review: Adam Husney MD - Family MedicineE. Gregory Thompson MD - Internal MedicineBrian D. O'Brien MD - Internal MedicineMartin J. Gabica MD - Family MedicineAvery L. Seifert MD - Urology
Current as of: September 23, 2020
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine & E. Gregory Thompson MD - Internal Medicine & Brian D. O'Brien MD - Internal Medicine & Martin J. Gabica MD - Family Medicine & Avery L. Seifert MD - Urology
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