Hyperkalemia is the medical term that describes a potassium level in your blood that’s higher than normal. Your body needs potassium. It is an important nutrient that is found in many of the foods you eat. Potassium helps your nerves and muscles, including your heart, work the right way. But too much potassium in your blood can be dangerous. Your blood potassium level is normally 3.6 to 5.2 millimoles per liter (mmol/L).
A report of high blood potassium isn’t true hyperkalemia. Instead, it may be caused by the rupture of blood cells in the blood sample during or shortly after the blood draw. The ruptured cells leak their potassium into the sample. This falsely raises the amount of potassium in the blood sample, even though the potassium level in your body is actually normal. When this is suspected, a repeat blood sample is done.
The most common cause of genuinely high potassium (hyperkalemia) is related to your kidneys, such as:
- Acute kidney failure
- Chronic kidney disease
Other causes of hyperkalemia include:
- Addison’s disease (adrenal failure)
- Alcoholism or heavy drug use that causes rhabdomyolysis, a breakdown of muscle fibers that results in the release of potassium into the bloodstream
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers (ARBs)
- Destruction of red blood cells due to severe injury or burns
- Excessive use of potassium supplements
- Type 1 diabetes
The symptoms of an elevated potassium level are nonspecific, and generally include malaise, palpitations, and muscle weakness. If symptoms do appear, they are usually mild and non-specific. You may feel some muscle weakness, numbness, tingling, nausea, or other unusual feelings. It usually develops slowly over many weeks or months and is often mild. It can recur.
If hyperkalemia comes on suddenly and you have very high levels of potassium, you may feel heart palpitations, shortness of breath, chest pain, nausea, or vomiting. Sudden or severe hyperkalemia is a life-threatening condition. It requires immediate medical care.