An Overview of Hyperkalemia

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Potassium is one of the most common chemical elements in our bodies, mostly existing inside our cells. Hyperkalemia is the term for high potassium levels in your blood. A normal potassium level for adults is considered 3.6 to 5.2 mEq/L.

If your level gets above 6 mEq/L, you will need treatment right away because elevated levels can become dangerous if they get too high. Hyperkalemia is often caused by kidney disease, but it can be caused by other illnesses and factors, such as heart disease, diabetes, cancer, and certain medications.

Understanding Electrolytes

To better understand why potassium levels are important and what may cause them to increase or decrease, it's helpful to know how electrolytes function in the body. Most people are familiar with electrolytes from Gatorade or Pedialyte commercials that stress rehydration after exercise (or vomiting and diarrhea in Pedialyte's case) to balance our electrolyte levels. While the information contained in the commercials is factual, it doesn't even begin to define the complexity of electrolytes and how critical they are to your body.

In the most simple terms, electrolytes are compound minerals that when dissolved in water separate into electrically charged ions. There are many types of electrolytes, but sodium, potassium, chloride, bicarbonate, calcium, sulfate, magnesium, and phosphate are considered the most important in the human body. Our bodies depend on potassium to regulate blood pressure, vascular tone, the normal function of insulin and various other hormones, gastrointestinal motility, acid-base balance, kidney function, and fluid and electrolyte balance.

Through hormones, specialized mechanisms, and transporters, the kidneys are responsible for monitoring the concentration and volume of electrolytes and water in the body. A basic example of how the kidneys regulate water and electrolytes is urination. When your body has excess fluid, your urine output is increased. When your body is dehydrated, your urine output is decreased. Any excess of electrolytes is expelled from your body through urine, sweat, and the digestive tract.

The kidneys have a strict margin of what is considered a low or high level of water or electrolytes in the body. When levels increase or decrease, the kidneys begin responding immediately. Experiencing thirst is a basic example of how our bodies respond to decreased water levels.

High potassium blood levels can disrupt the way certain organ systems function and can become fatal if left untreated. Because hyperkalemia can become quite dangerous, elevated potassium levels must be taken seriously, even if they are not yet producing any symptoms.

Symptoms

Potassium plays an important role in heart and neuromuscular function, so when levels are high, the heart, nerves, and muscles are often affected. With mild elevations of potassium, you may not have any symptoms, but as levels increase, your symptoms may include:

  • Muscle weakness or spasms
  • Fatigue
  • Shortness of breath and hyperventilation
  • Nausea and vomiting
  • Paralysis
  • Tingling sensations
  • Heart arrhythmias (irregular heart rhythms), which are one of the more serious complications
  • Confusion
  • Seizures, coma, and death when the levels are very high

Causes

There are many factors that can contribute to increased potassium levels, but the most common is kidney problems like acute kidney failure or chronic kidney disease. Other common potential causes include:

  • Addison's disease
  • Certain medications like angiotensin II receptor blockers, angiotensin-converting enzyme (ACE) inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), and beta blockers
  • Ingesting too much potassium, such as in food, potassium supplements, or salt substitutes
  • Dehydration
  • Type 1 diabetes
  • Red blood cells being destroyed because of burns or other severe injuries
  • Tumor lysis syndrome
  • Blood transfusions

Diagnosis

It's important to make sure that you have true hyperkalemia. Hyperkalemia is diagnosed through blood tests that check kidney function and potassium levels, urine tests, and/or cardiac tests. Between all of these tests, your doctor will be able to diagnose you with hyperkalemia fairly quickly if you truly have it.

Sometimes your blood test may show that you have a high level of potassium when you actually don't; this is known as pseudohyperkalemia. This can happen if the red cells in the blood sample rupture, releasing potassium into the sample. It can also happen if an extremely tight tourniquet is used for several minutes during the blood draw while looking for a vein, especially if you open and close your fist repeatedly to expand your veins.

Pseudohyperkalemia can also occur when you have a very high white blood cell or platelet count. If a high potassium level is found when you have no obvious reason for hyperkalemia, and if you don't have any symptoms or signs of hyperkalemia, the blood test needs to be repeated.

With pseudohyperkalemia, the serum potassium level is significantly higher than the plasma potassium level. Because of this, some doctors prefer blood tests done using plasma to make sure you don't have pseudohyperkalemia.

Treatment

Most of the time hyperkalemia is mild and can be treated by simply restricting potassium in your diet and treating the underlying cause. If it's more severe, treatment options may include:

  • Diuretics (water pills)
  • Intravenous (IV) glucose and insulin
  • IV calcium
  • Dialysis
  • Potassium-removing agents like patiromer, which binds potassium in the digestive tract in exchange for calcium

Diet

Eating a healthy diet that limits your potassium intake is important if you have kidney disease or other conditions that put you at high risk of developing hyperkalemia. This includes limiting or avoiding foods that are high in potassium, such as many dairy products, vegetables, fruits, dry beans, and nuts.

A Word From Verywell

Hyperkalemia is a potentially dangerous condition, but it can be successfully reversed. When low potassium levels occur, it's important to have your doctor quickly assess your immediate level of danger and work to get your blood potassium levels back to normal. It's also critical to find the underlying cause of your hyperkalemia so it can be treated, if necessary, and so that steps can be taken to prevent it from happening again.

Signs and Symptoms of Hyperkalemia (High Potassium)
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