This tool helps you think through whether your symptoms warrant contacting a doctor or seeking urgent care — it does not diagnose hyperkalemia (high potassium) and cannot replace a blood test or a clinician’s judgment. If you have any doubt, contact a healthcare provider rather than relying on this checklist.
Check any that apply to you right now:
Important: this checker cannot measure your potassium. Only a blood test can. Many people with dangerously high potassium have no symptoms at all, so a “low concern” result does not rule it out. If you have chest pain, fainting, a very slow or irregular heartbeat, or sudden weakness, call 911 or your local emergency number. See our medical disclaimer.
What hyperkalemia is
Hyperkalemia means the level of potassium in your blood is higher than normal. Potassium helps nerves fire and muscles contract, including the heart muscle. Your kidneys normally remove extra potassium, so a high level usually means the kidneys are not clearing it well, something is moving potassium out of your cells, or you are taking in more than your body can handle, often because of a medicine.
| Blood potassium (mmol/L) | Usual description | What typically happens |
|---|---|---|
| 3.5 to 5.0 | Normal (labs vary slightly) | Nothing needed |
| 5.1 to 5.9 | Mild | Repeat the test, review medicines and diet |
| 6.0 to 6.4 | Moderate | Prompt treatment, often an ECG |
| 6.5 or higher | Severe | Medical emergency, treated in hospital |
Exact cutoffs differ slightly between guidelines and labs. ECG changes matter as much as the number: a potassium of 6.0 with heart rhythm changes is treated more urgently than a 6.2 with a normal ECG.
Symptoms, and why they are easy to miss
Mild hyperkalemia usually causes no symptoms and is found on a routine blood test. As levels rise, people may notice:
- Muscle weakness or heaviness, often in the legs first
- Tingling or numbness
- Fatigue
- Nausea
- Palpitations, or a heartbeat that feels slow, skipped or irregular
These are vague and overlap with many other conditions, which is why the checker gives heart-related symptoms extra weight. The real danger of high potassium is an abnormal heart rhythm, and that can happen suddenly.
Who is most at risk
- Chronic kidney disease, the most common underlying cause
- Heart failure, especially when treated with potassium-raising drugs
- Diabetes, which can affect the hormones that control potassium
- Medicines: ACE inhibitors (lisinopril, enalapril), ARBs (losartan, valsartan), spironolactone and eplerenone, potassium-sparing diuretics, NSAIDs such as ibuprofen, trimethoprim, heparin, and calcineurin inhibitors such as tacrolimus
- Potassium supplements and salt substitutes, many of which are potassium chloride
A high result is sometimes a false alarm
If red blood cells break during or after the blood draw (hemolysis), they release potassium into the sample and the result reads falsely high. This is called pseudohyperkalemia. Clenching your fist hard during the draw or a long delay before the sample is processed can cause it too. That is why an unexpected high result is often repeated before treatment, unless you have symptoms or ECG changes.
How it is treated
Treatment depends on how high the level is and whether the heart is affected. In an emergency, hospitals give intravenous calcium to protect the heart, insulin with glucose and inhaled albuterol to push potassium into cells, and then something to remove potassium from the body. Over the longer term, options include adjusting medicines, a lower-potassium diet guided by a dietitian, diuretics, and potassium binders. Our potassium binder cost calculator and Lokelma vs Kayexalate comparison explain the binder options.
Related reading
- Lokelma vs Kayexalate: speed, safety and cost compared
- Potassium binder cost calculator
- Invokana vs Jardiance: kidney and heart data
- Chronic and specific conditions
Frequently asked questions
What potassium level is dangerous?
Levels of 6.5 mmol/L or higher are generally treated as an emergency, and levels of 6.0 or higher need prompt attention, especially with ECG changes or symptoms. Your doctor interprets the number alongside your kidney function and heart tracing.
Can eating bananas cause high potassium?
Not in people with healthy kidneys, which easily remove extra dietary potassium. Diet matters mainly for people with reduced kidney function or those taking potassium-raising medicines.
Can you feel high potassium?
Often not. Many people have no symptoms even at dangerous levels, which is why regular blood tests matter if you have kidney disease or take medicines that raise potassium.
Should I stop my blood pressure medicine if my potassium is high?
No, not on your own. ACE inhibitors, ARBs and spironolactone often protect the heart and kidneys. Your doctor may adjust the dose, add a binder, or change something else instead.
Sources
- Simon LV, et al. Hyperkalemia. StatPearls, NCBI Bookshelf
- High potassium level (hyperkalemia). MedlinePlus, U.S. National Library of Medicine
- Lokelma, Veltassa and sodium polystyrene sulfonate prescribing information, DailyMed
About this article
Written by the Health Linear Editorial Team from primary sources such as FDA prescribing information, DailyMed, NIH and peer-reviewed studies, which are linked in the article. Last updated October 27, 2026.
Read our editorial process and medical disclaimer. Spotted an error? Tell us and we will correct it.