Potassium (Serum) – Mass Concentration
This test measures the amount of potassium, a mineral essential for heart function and nerve signaling, in your blood serum.
["Potassium levels help assess heart health and electrolyte balance."]
Key facts at a glance
- LOINC
- 3429-8
- Short code
- CANRU
- Synonyms
- Canrenone Ur-mCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, leak-proof urine collection container; preferably a clean-catch midstream container without preservatives.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–99 years
- Method
- High-Performance Liquid Chromatography (HPLC) with tandem mass spectrometry (LC-MS/MS)
- CPT
- 80299
- SNOMED
- 39579001
- Specimen volume
- 10-20 mL of urine
- Stability
- Stable for 24 hours at room temperature (15-25°C); up to 7 days refrigerated at 2-8°C; up to 30 days frozen at -20°C or below. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 48–96 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to check for conditions affecting potassium levels, such as kidney problems, heart issues, or certain medications that alter potassium balance. It’s also used to monitor patients with conditions like heart failure, kidney disease, or those taking diuretics or laxatives.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on certain medications (e.g., potassium-sparing diuretics), discuss this with your doctor before the test.
What Happens During the Test?
A healthcare provider will collect blood from a vein in your arm. The sample is sent to a lab for analysis using a method that detects potassium concentration in your serum.
What the Results Mean
Results help determine if your potassium levels are too high (hyperkalemia) or too low (hypokalemia), which can affect muscle function, heart rhythm, or other bodily processes. Your doctor will interpret these results in the context of your overall health.
Reference range
Reference values vary by laboratory; consult your lab's specific reference range. Typically reported as mcg/mL or ng/mL of canrenone excreted in urine.N/A
No special preparation required. Patient should maintain normal hydration unless instructed otherwise by physician. Inform the laboratory of all medications being taken, particularly potassium-sparing diuretics such as spironolactone or canrenone.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal potassium levels can indicate underlying health issues, such as kidney dysfunction, dehydration, or metabolic disorders. High potassium may cause irregular heartbeats, while low potassium can lead to muscle weakness or cramps. Regular monitoring is crucial for patients with chronic conditions like diabetes, heart disease, or those on long-term medications.
Short name
Serum Potassium
Frequently asked questions
How often should potassium levels be checked?
Can diet affect potassium test results?
What if my potassium level is out of range?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy