High potassium: Causes, Symptoms and Treatments

Picture of High Potassium


What is High potassium?

Potassium is an essential electrolyte, which is a mineral that your body needs to function correctly. This mineral is particularly important for your nerves and muscles. All of your muscles need potassium, including your heart. Healthy kidneys flush excess potassium out of your body.

While potassium is indeed important, getting too much can be just as bad or worse than not getting enough of the nutrient. Hyperkalemia is a condition that occurs when your blood contains too much potassium.

According to the Mayo Clinic, a normal range for potassium is between 3.6 and 5.2 millimoles per liter (mmol/L) of blood. A potassium level higher than 5.5 mmol/L is critically high, and a potassium level over 6.0 mmol/L can be life-threatening. This condition is dangerous, and requires prompt medical attention to prevent potential complications.

Causes of High potassium

Often, 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:

  1. Acute kidney failure
  2. Chronic kidney disease

Other causes of hyperkalemia include:

  1. Addison’s disease (adrenal failure)
  2. Alcoholism or heavy drug use that causes rhabdomyolysis, a breakdown of muscle fibers that results in the release of potassium into the bloodstream
  3. Angiotensin-converting enzyme (ACE) inhibitors
  4. Angiotensin II receptor blockers (ARBs)
  5. Destruction of red blood cells due to severe injury or burns
  6. Excessive use of potassium supplements
  7. Type 1 diabetes

Symptoms of High potassium

Hyperkalemia is a relatively common disturbance of electrolytes. Most cases of hyperkalemia are mild and may not produce any symptoms at all. Typically, hyperkalemia that develops slowly over time produces fewer symptoms than a sudden rise in potassium levels.

Usually, symptoms do not become apparent until potassium levels are very high (7.0 mEq/l or greater). Sometimes people with hyperkalemia report nonspecific symptoms such as muscle weakness, tiredness, tingling sensations, or nausea.

A slow heartbeat and weak pulse are more serious symptoms, since these may signal an effect on the electrical activity of the heart. Potassium is responsible for maintaining normal heart rhythm and hyperkalemia can have potentially life-threatening effects. While mild hyperkalemia probably has a limited effect on the heart, moderate hyperkalemia can changes in the electrocardiogram (EKG, ECG) recording (EKG is an electrical reading of the activity of the neuromuscular activity of the heart), and severe hyperkalemia can cause the heart to stop beating.

Hyperkalemic periodic paralysis is a rare inherited disorder that can result in sudden hyperkalemia accompanied by muscle paralysis.

Treatment for High potassium

You will need emergency treatment if your potassium level is very high, or if you have danger signs, such as changes in an ECG.

Emergency treatment may include:

  • Calcium given into your veins (IV) to treat the muscle and heart effects of high potassium levels
  • Glucose and insulin given into your veins (IV) to help lower potassium levels long enough to correct the cause
  • Kidney dialysis if your kidney function is poor
  • Medications that help remove potassium from the intestines before it is absorbed
  • Sodium bicarbonate if the problem is caused by acidosis
  • Water pills (diuretics) to decrease total potassium

Changes in your diet can help both prevent and treat high potassium levels. You may be asked to:

  • Limit or avoid asparagus, avocados, potatoes, tomatoes or tomato sauce, winter squash, pumpkin, and cooked spinach
  • Limit or avoid oranges and orange juice, nectarines, Kiwis, raisins, or other dried fruit, bananas, cantaloupe, honeydew, prunes, and nectarines
  • Avoid taking salt substitutes if you are asked to eat a low-salt diet

Your doctor may make the following changes to your medicines:

  • Reducing or stopping potassium supplements
  • Stopping or changing the doses of medicines you are taking, such as ACE inhibitors, angiotensin receptor blockers, spironolactone (Aldactone), amiloride (Midamor), or triamterene (Dyrenium)
  • Taking “loop diuretics” to reduce potassium and fluid levels if you have chronic kidney failure

It is important to follow your health care provider’s directions when taking your medicines:

  • Do not stop or start taking medicines without first talking to your health care provider
  • Follow your prescribed schedule as closely as possible
  • Always tell your health care provider about any other medicines, vitamins, or supplements you are taking

When To Call Your Doctor or Health Care Provider About High potassium:

  • Nausea that interferes with your ability to eat, and is unrelieved by prescribed medication.
  • Vomiting (vomiting more than 4-5 times in a 24 hour period).
  • Severe constipation, unrelieved by laxatives, lasting 2 to 3 days.
  • Muscle weakness, poor appetite that does not improve.
  • Feeling your heart beat rapidly (palpitations).