Potassium is one of the minerals in the body. Most of the potassium is inside the body cells and a small but important percentage circulates in the blood. A potassium blood test can measure how much potassium is in the blood. Normal levels are between 3.5 to 5 meq/L. The body needs potassium to work normally. It keeps the heart beating and helps the nerves and muscles work. Potassium is found in most foods that you eat. The extra potassium that the body does not need is lost through the urine and stool. Too much or too little potassium in the body can cause problems.

While all body cells need potassium to function properly, high or low potassium levels can become dangerous and lead to serious arrhythmias or heart problems and even stop the heart. Having too much potassium in the blood is a condition called "hyperkalemia". Hyperkalemia can cause muscle weakness, inability to get up from a chair or an abnormal heart rhythm or palpitations. Too little potassium in the blood is called "hypokalemia". Low potassium can happen in people who have a lot of vomiting or have excessive diarrhea. It can also happen in people taking large doses of medicines called "diuretics", such as hydrochlorothiazide or furosemide (brand name: Lasix). Hypokalemia can lead to muscle weakness and slow down of the bowels. When kidney function is adequate and diuretics are prescribed, your physician may add potassium supplements to counteract the losses through the urine.

High Potassium is a major concern for those with chronic kidney disease. One of the jobs of the kidneys is to keep the right amount of potassium in the body. As the kidney function declines, the capacity of the kidneys to get rid of extra potassium that was ingested decreases, and potassium can build up to harmful levels in the blood. When the kidney function is below 20% you are at chronic risk of higher potassium and may have to make adjustments in your diet to keep a balance.

Diet is the first line of defense against hyperkalemia or hypokalemia. Eating too much food that is high in potassium can cause potassium levels to rapidly rise to unsafe levels, especially in people with advanced kidney disease. It is important to talk to your doctor about what diet is right for you and your level of kidney function. They may advise moderation in use of high potassium foods or a low potassium diet. In addition, at times, doctors may recommend a change in your medications that can contribute to hyperkalemia or add medications that increase loss of potassium from your body. On the other hand, low potassium levels are treated with a higher potassium diet and even by potassium supplements.

If you think you are at risk for potassium problems ask your doctor for a list of food that contain high and low potassium. There are many resources available on the internet on this topic. You can also take a quiz here to see if you are at risk.