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Potassium

Potassium levels: what do they tell you about your electrolyte balance?

Potassium is critical for heart and muscle health. Regular monitoring helps detect imbalances early, especially if you take medications affecting electrolytes.

Doctor's Assessment Included

Reference Ranges

See the value that applies to you:

Age years

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Your reference range

mmol/l

3,4 5,2 mmol/l

Reference ranges by group, in mmol/l
Age	Sample	Reference range (mmol/l)	Relative scale
6 years and older	· Plasma	3,4–4,9 mmol/l	3,4 4,9
6 years and older	· Serum	3,8–5,2 mmol/l	3,8 5,2

3,4 5,2 mmol/l

Serum reads higher than plasma because platelets release potassium during clotting.

Source: NVKC Reference population: Dutch general-practice population (NUMBER, n = 7,574,327)

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

Check your own value

Potassium: what this test measures

This test measures the level of potassium in your blood. Even small changes in potassium levels can significantly affect heart rhythm and muscle function.

Potassium: why this value matters

Potassium is critical for maintaining heart rhythm, blood pressure regulation, and proper muscle function. Both low and high levels can be dangerous and may require medical attention. Consult your healthcare provider for interpretation.

Potassium: how the blood test works

Referral: No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw: A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Which test: on its own €7,- InsideTracker Recovery · €139,- · Complete Metabolic Panel · €149,- · InsideTracker · €399,- · Whoop · €499,-
Where: 650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Potassium: when is testing worthwhile?

Testing may be recommended as part of routine health screening, if you take blood pressure medications, have kidney disease, or experience symptoms such as muscle weakness or heart palpitations.

Potassium: symptoms of a high or low value

Low Levels

Symptoms of low potassium may include muscle weakness, cramps, fatigue, constipation, and heart rhythm irregularities. Severe deficiency can be life-threatening.

High Levels

High potassium may cause muscle weakness, tingling, nausea, and dangerous heart rhythm disturbances. It requires prompt medical evaluation, especially in those with kidney disease.

Potassium: lifestyle and this value

Include potassium-rich foods such as bananas, potatoes, spinach, avocados, and beans in your diet. If you take medications that affect potassium, work with your healthcare provider on monitoring.

Potassium: frequently asked questions

Why is potassium important for the heart?

Potassium helps regulate the electrical signals that control heartbeat. Both too little and too much potassium can cause dangerous heart rhythm problems.

Can medications affect potassium levels?

Yes, certain blood pressure medications, diuretics, and other drugs can raise or lower potassium. Always inform your healthcare provider about all medications you take.

What is the best food source of potassium?

Bananas are well-known, but potatoes, beans, spinach, avocados, and yoghurt are also excellent sources. A varied diet typically provides adequate potassium.

Potassium: sources

den Elzen WPJ, Brouwer N, Thelen MH, Le Cessie S, Haagen I-A, Cobbaert CM. NUMBER: standardized reference intervals in the Netherlands using a 'big data' approach. Clin Chem Lab Med 2018;57(1):42-56. (retrieved 2026) doi.org

Test Products

This marker is included in the following test panels.

InsideTracker

InsideTracker Recovery

A 10-biomarker recovery panel inspired by InsideTracker's Recovery category — muscle enzymes, liver values, electrolytes, magnesium and vitamin D behind your recovery score.

Magnesium CRP (C-Reactive Protein) ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) GGT (Gamma-Glutamyl Transferase) Albumin Creatine Kinase (CK) Sodium Potassium Vitamin D (25-OH)

€139,-

Health Checkups

Complete Metabolic Panel

Comprehensive metabolic panel: electrolytes, kidney, liver, glucose, HbA1c, and protein.

Bicarbonate Calcium Chloride Potassium Sodium Glucose (Fasting) HbA1c (Glycated Hemoglobin) Albumin ALP (Alkaline Phosphatase) ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) Bilirubin (Total) Urea (BUN) Creatinine eGFR (Estimated Glomerular Filtration Rate) Total Protein Bilirubin (Direct) Bilirubin (Indirect)

€149,-

InsideTracker

An InsideTracker blood test with 35 biomarkers: heart, hormones, metabolism, inflammation, recovery and iron status. Measured in the Netherlands.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol GGT (Gamma-Glutamyl Transferase) Cortisol DHEA-S Estradiol (E2) Free Testosterone Total Testosterone Folate (Folic Acid) Vitamin B12 Calcium Ferritin Iron (Serum) Magnesium Potassium Progesterone Sodium Transferrin CRP (C-Reactive Protein) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin AST (Aspartate Aminotransferase) Vitamin D (25-OH) Insulin (Fasting) Leukocyte Differential Creatine Kinase (CK) Transferrin Saturation Triglycerides Basic Blood Count HOMA-IR Cholesterol/HDL Ratio Non-HDL Cholesterol LDL/HDL Ratio

€399,-

Whoop

A 45-biomarker comprehensive health panel inspired by WHOOP Advanced Labs — a deep look at metabolism, cardiovascular risk, hormones, liver, kidney and inflammation.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol Cortisol DHEA-S Estradiol (E2) Free Testosterone FSH (Follicle Stimulating Hormone) LH (Luteinizing Hormone) Total Testosterone Bicarbonate Calcium Chloride Ferritin Iron (Serum) Magnesium Potassium Sodium Transferrin CRP (C-Reactive Protein) Homocysteine Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin HOMA-IR ALP (Alkaline Phosphatase) AST (Aspartate Aminotransferase) Bilirubin (Total) Total Protein Urea (BUN) Creatinine Vitamin D (25-OH) eGFR (Estimated Glomerular Filtration Rate) Insulin (Fasting) Leukocyte Differential Transferrin Saturation Lipoprotein(a) Triglycerides Basic Blood Count Bilirubin (Direct) Bilirubin (Indirect) Cholesterol/HDL Ratio Non-HDL Cholesterol LDL/HDL Ratio

€499,-