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Serum Potassium (Potassium Ion Concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of potassium, a mineral essential for heart function and nerve signaling, in your blood.

Quick summary

["Potassium levels help ensure your heart rhythm and muscle contractions work properly."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73147-1
Short code
Sotalol ind plt IgM SerPl Ql FC
Synonyms
Sotalol ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for high or low potassium levels, which can affect heart health, muscle function, or other body systems. It’s often done if you have symptoms like muscle weakness, irregular heartbeat, or kidney issues, or if you’re taking medications that affect potassium levels.

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 blood draw if your test involves a specific timing (e.g., 24-hour urine). Wear a loose shirt for easy access.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it’s quick and painless. The blood sample is then sent to a lab for analysis.

What Do the Results Mean?

Results are compared to a standard range for healthy adults. Too little or too much potassium can signal underlying health concerns, such as kidney problems, heart conditions, or certain medications affecting balance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal potassium levels can cause serious health risks, including dangerous heart rhythms, muscle weakness, or even seizures. High potassium (hyperkalemia) may occur in kidney disease or excessive potassium intake, while low potassium (hypokalemia) can result from vomiting, diarrhea, or certain medications. Regular monitoring helps manage conditions like heart disease, diabetes, or electrolyte imbalances.

Short name

Serum Potassium

Frequently asked questions

How often is this test done?
This test is often done as a routine check or when symptoms or medical conditions suggest potassium imbalance. Your doctor may order it monthly, quarterly, or as needed based on your health status and medications.
What are common causes of low potassium?
Common causes of low potassium include vomiting or diarrhea, excessive sweating, certain medications (like diuretics), kidney problems, or poor nutrition (e.g., low intake of bananas, potatoes, or leafy greens).
What are common causes of high potassium?
High potassium levels can result from kidney failure, certain medications (like potassium-sparing diuretics), severe dehydration, or conditions like Addison’s disease. Rarely, rapid cell breakdown (e.g., from trauma or certain cancers) can also raise potassium levels.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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