Hypokalemia

What is hypokalemia?

Hypokalemia means that the amount of potassium in your blood is lower than normal. Potassium is one of the most important minerals in your body. It is very important for normal heart and nervous system function. For example, a very low blood level of potassium can lead to serious and even fatal heart rhythm problems.

You get potassium from many different foods. Your body normally keeps only as much potassium as it needs and gets rid of the rest.

How does it occur?

There are many ways hypokalemia can happen. Often it happens because your body is losing more fluid than normal. You may lose more fluid when:

• You have had a lot of vomiting or diarrhea.
• You are taking medicine that makes the body get rid of too much potassium. For example, some diuretics (also called “water pills”) help the body get rid of fluid by causing you to urinate more. You may lose more potassium in the urine.

Hormone problems are another cause of low potassium. For example:

• You may have too much aldosterone, which is a hormone that controls how much potassium is in your body.
• You may have too much cortisol. This may happen because the body is making too much. Or it may happen if you are taking cortisol medicine (called steroids or corticosteroids).

Other possible causes of low potassium are:

• You are not getting enough potassium from your diet or from potassium supplements prescribed by your provider.
• You have been sweating a lot during exercise.
• You have kidney disease that causes you to get rid of too much potassium.
• You have an eating disorder, such as bulimia.

What are the symptoms?

When hypokalemia is mild, it usually does not cause any symptoms. When it does cause symptoms, the most common one is tiredness, especially of the muscles. The muscles may feel weak and they may tend to cramp.

If your potassium gets too low, it can also affect the heart muscle and the heart’s rhythm. Your heart may beat fast or irregularly.

How is it diagnosed?

Low potassium is diagnosed with a blood test.

• The normal potassium range for adults in most labs is 3.5 to 5.5 milliequivalents (mEq) per liter. This range may vary slightly from lab to lab.
• Below 3.5 mEq/L is considered hypokalemia.
• Below 2.5 mEq/L is considered severe hypokalemia.

If you have one of the more uncommon reasons for having low potassium, you will need more tests, such as:

• other blood tests
• urine tests
• special X-rays or scans of your kidneys and pituitary gland.

How is it treated?

For the common causes of low potassium, such as stomach flu or heavy exercise, you can usually replace lost potassium by eating foods rich in potassium or by drinking sports drinks. If you are taking a diuretic medicine that makes you lose potassium, you may need to eat foods that have a lot of potassium every day, or you may need to take potassium tablets every day. You can ask your healthcare provider if a diuretic that helps you keep your potassium would work for you. You may have blood tests on a regular basis to check your potassium level.

If your hypokalemia is severe, you need treatment right away, which may include getting potassium by IV (by vein) so you can raise your level of potassium quickly to prevent heart complications.

If low potassium is caused by an underlying medical problem, such as too much aldosterone or cortisol, the underlying problem will need to be treated.

How long will the effects last?

In most cases of mild hypokalemia the potassium will return to normal a few days after you start taking potassium. If your potassium was low enough to cause symptoms, it may take a few days of treatment for the weakness and other symptoms to go away.

How should I take care of myself?

It is very important to follow your healthcare provider’s advice regarding:

• eating high-potassium foods
• taking your potassium medicine every day, if prescribed
• checking your potassium regularly as recommended by your provider.

Many fruits and vegetables, as well as other foods, are good sources of potassium. Some examples of foods rich in potassium are:

• melons, bananas, oranges, and pears
• yogurt, 2% milk, soy milk, and low-fat cottage cheese
• beans and lentils
• raisins
• peanut butter
• sunflower seeds
• papayas, mangoes, and kiwis
• prune juice
• tomatoes and avocados
• potatoes and sweet potatoes with skin
• pumpkin, asparagus, and Brussels sprouts
• salmon, dark turkey meat, and lean beef
• swiss chard.

What can I do to prevent hypokalemia?

If you are an active exerciser or you have had a bout of the stomach flu, be sure to use sports drinks or a few potassium-rich foods to prevent low potassium.

Low potassium caused by medicine you are taking can be prevented by replacing the lost potassium with high-potassium foods or potassium pills. Be sure to keep your appointments to get your potassium checked.