Hypokalemia occurs when the blood’s potassium levels are too low. A normal level of potassium is 3.6-5.2 millimoles per liter. Levels below 3.6 are considered low. Anything below 2.5 millimoles per liter is very low (Mayo Clinic).
Potassium is an electrolyte. It is necessary for nerve and muscle cell functioning. It is especially important for the functioning of muscle cells in the heart. The kidneys control potassium levels. Excess potassium leaves the body through urine or sweat.
Hypokalemia is also called hypokalemic syndrome, low potassium syndrome, nephritis, and hypopotassemia syndrome.
Hypokalemia is a symptom or side effect of other conditions and some medications. Hypokalemia usually occurs when too much potassium is lost through urine, sweat, or bowel movements. In rare cases, hypokalemia is caused by too little potassium intake.
Many things can cause potassium loss. The most common cause is the use of diuretics, or pills that cause urine production. Diarrhea, vomiting, and excessive use of laxatives can also cause symptoms. Excessive sweating due to heat or exercise can cause hypokalemia.
Other causes of hypokalemia include:
There are usually no signs of hypokalemia. Some people suffer from weakness, fatigue, constipation, and muscle cramping. In more severe cases, heart arrhythmias, or abnormal rhythms may occur. This is most common in people with heart problems.
Other potential complications include low blood pressure, muscle twitches, and loss of muscle control (such as in the bowel). Hypokalemia can also cause mineral deficiency and loss of muscle in the skeletal system. Other symptoms include excessive urination, extreme thirst, loss of appetite, nausea, and vomiting.
Hypokalemia is usually diagnosed during routine blood tests, which check the levels of potassium in the blood. Testing because of symptoms or complications is rare.
A doctor may prescribe medication that will treat the underlying condition. In some cases, potassium supplements are recommended.
Treating the underlying condition usually resolves this problem. Most people learn to control their potassium with minimal impact on their lives.
In rare cases, hypokalemia can lead to paralysis or respiratory failure.
Eating a diet that is rich in potassium can help prevent and treat low blood potassium. If you are taking potassium supplements, discuss your diet with your doctor to make sure you are not taking too much potassium. Good sources of potassium include: