Are you like me in that for most of your life, the only time you saw a doctor was if you were sick, hurt or required to have a physical?

In fact, for most of my life, I was my own doctor. I’ve set some of my own broken bones, removed stitches, given myself a tetanus shot, drew my own blood for a nurse and drained fluid from my knee. I’ve had partial tears of the ACL and MCL in both of my knees and never had surgery to repair them. I was told by a top orthopedic podiatrist in my state that I needed to have both knee joints replaced with artificial ones and that without new joints there was no way I could spend 8 hours a day on my feet. Since that time, I worked as a retail manager where I was on my feet 10-14 hours a day and as an electrical meter reader where I walked an average of 12-15 miles a day and some days up to 20 miles, and yet, no knee surgery.

However, now that I’m older and have type 2 diabetes and high blood pressure, I have to see my doctor at least twice a year. She orders blood and urine tests to monitor not only my diabetes, but to monitor many other health concerns.

One of those regular blood tests is a comprehensive metabolic panel (CMP). This test measures blood sugar, electrolyte and fluid balance, along with kidney and liver function. The CMP gives you results for albumin, blood urea nitrogen (BUN), calcium, carbon dioxide, chlorine, creatinine, glucose, potassium, sodium, total bilirubin, total protein, alanine aminotransferase (ALT), alkaline phosphate (ALP) and aspartate aminotransferase (AST). Over the next few weeks, I hope to cover what these are and what low or high levels mean to you.

Today, I’ll talk about potassium level in the blood. Potassium in the blood is measured in mmol/L (millimoles per liter). The normal level of potassium in the blood ranges from 3.5 to 5.0 mmol/L. My last CMP showed my potassium level was 5.0, but the one prior to that was 5.1, just over the normal limit. So, what does that mean to me and to you?

Potassium is vital for muscle function, including the heart muscle. That’s why many experts recommend eating bananas, which are high in potassium, if you have leg cramps.

Too much potassium is known as hyperkalemia. The most common cause of hyperkalemia is kidney disease, meaning the kidneys are not removing enough potassium from the blood. It can also be caused by certain medications or by taking too much potassium supplements. Some salt substitutes also contain high levels of potassium.

Diseases, such as Addison’s disease cause the body to produce too little aldosterone, a hormone that tells the kidney to remove potassium from the blood.

Having too much potassium in the blood can also be an indication of a condition called hemolysis (the breaking down of red blood cells), rhabdomyolysis (breaking down of muscle tissue), burns, traumas and uncontrolled diabetes.

Too much potassium in the blood can cause an abnormal heart rhythm, a slow heart rate and weakness. Consider this – when a veterinarian puts down a pet, they often use a concentrated solution of potassium, which stops the heart.

Too little potassium is called hypokalemia. This can be caused by frequent vomiting, diarrhea, improperly functioning kidneys or adrenal glands and certain medications such as diuretics (water pills). Some diseases such as Cushing’s syndrome, Gitelman syndrome, Liddle syndrome, Bartter syndrome and Fanconi syndrome can be associated with low potassium levels.

Having too little potassium can make you weak, fatigued, muscle cramping, muscle twitching, constipation and arrhythmia (abnormal heart beat).

One way to learn the reason for having a low potassium level is by your doctor performing a urine test, which can detect if too much potassium is being passed out in the blood.

Both hyperkalemia and hypokalemia can have a direct impact on your heart and kidneys. That’s why it’s important to maintain the rather narrow balance of 3.5-5.0 mmol/L of potassium in the blood and why it’s important to have you doctor order a CMP blood test on a regular basis.