Dr. Toshi Is In! "What are electrolytes?"

Dear Dr. Toshi,

What are electrolytes?

     At some time in your life, you may have been told to drink fluids that have electrolytes. Today I'll explain what the electrolytes are, why we need them, and how we test your blood for them.

Did you know that our bodies have electric charges? An electric charge can be positive or negative, and it's a basic property of the particles that atoms are made of. Specifically, atoms are made of protons (which have a positive charge), neutrons (which are neutral and have no charge), and electrons (which have a negative charge). Atoms connect to other atoms, forming molecules, and molecules connect to other molecules, forming cells. Finally, cells connect to other cells, forming organs and most of the other tissues that make up our bodies. So, our bodies have electric charges!

Basically, electrolytes like sodium, potassium, calcium, magnesium, chloride, etc., are atoms that have positive or negative electric charges because they have too many or too few electrons. For example, sodium has one positive charge. The same for potassium. Calcium and magnesium each have a positive charge of two. Chloride has a negative charge of one. We eat and drink electrolytes all the time. In fact, that's how we usually replenish our electrolytes. Table salt is sodium chloride, for instance. People who run marathons and sweat a lot, and people who get very sick and have a lot of diarrhea lose a lot of water and electrolytes, so rather than rehydrating with plain water, they rehydrate with fluids that have electrolytes.

Electrolytes are in our blood, urine, and all of the other fluids and tissues in our bodies, and they're absolutely essential for our bodies to function properly. Without them, your heart, brain, eyes, nerves, and muscles would instantly stop working.

So, we need all these electrolytes, and we also need to have the right level of each. We don't want to be too low on any of them, but we also don't want to be too high. For example, too much sodium (in salt, which is sodium chloride, as I mentioned above) can cause your body to retain too much fluid, resulting in high blood pressure and swelling (which is called "edema"). Many years ago, I had a young man come to my clinic with swelling everywhere in his body. I found out that he had eaten a lot of very salty food, including potato chips, salsa, onion dip, beef jerky, and other salty snacks, the night before while watching football on TV, and that's what had caused all the fluid retention and swelling in his body. His blood pressure was also high because of all the excess fluid in his bloodstream.

A high level of sodium can also cause extreme tiredness (lethargy), seizures, muscle spasms, and even comas. A low level of potassium can cause abnormal heart rhythms, muscle problems, and other symptoms. Also, the acidity of your body is balanced by electrolytes, and electrolytes also help move nutrients into your cells and remove wastes from your cells.

So, it's good to have your electrolyte levels checked from time to time at your clinic. We check the levels of electrolytes in a blood test called the "Basic Metabolic Panel." This blood test tells us your levels of sodium, potassium, chloride, bicarbonate, and calcium, along with your blood glucose (sugar) level and BUN (blood urea nitrogen) and creatinine, which tell us about your kidney function.

Dr. Toshiko (Toshi) Luckow, MD a Family Medicine physician at the West River Health Services hospital and clinics.