Can Drinking Too Much Water Cause Low Potassium?

Water is essential to human life, but drinking an excessive amount can lead to a potentially life threatening loss in the mineral potassium. Nutrition professor with North Dakota State University Julie Garden-Robinson, Ph.D., states that excessive water consumption leads to a dangerous condition known as "water intoxication." This condition can lead to urinary loss of potassium.

Potassium is one mineral in a class of minerals known as electrolytes. They help move positively and negatively charged ions in and out of your cells so your nervous system can trigger cell functions electrically, such as muscle contraction and relaxation. Excessive fluid loss causes your body to lose electrolytes, leading to an electrolyte imbalance. While electrolyte imbalance is most typically associated with vomiting, diarrhea and sweating, increased urination may also flush potassium out of your body. A 1993 case study in the journal "Nephron" showed that water intoxication can exaggerate the body's response to peptide hormones that flush sodium and water out of the body. The flushing of fluids leads to potassium deficiency, otherwise known as hypokalemia.

Drinking too much water can also lead to depletion of magnesium in your body — a mineral essential to maintaining potassium levels. Magnesium can be flushed out of your body through your urine the same way as potassium. Without adequate magnesium in your body, potassium has difficulty entering into your cells where potassium storage takes place. When the potassium cannot enter your cells for storage, your kidneys will eventually process it and flush it out through your urine.

If your water consumption is leading to a loss of potassium in your body, you may begin to notice low energy levels, muscle cramps, intestinal distress and muscle spasms. If your electrolyte imbalance worsens, the symptoms may worsen as well, requiring immediate medical attention with supplemental potassium. Hypokalemia can lead to irregular heart rhythms and muscular paralysis.

If you take certain diuretics that remove potassium from your body, have alcoholism, experience regularly vomiting or diarrhea, have an eating disorder, low magnesium levels or congestive heart failure, you may be at risk for low potassium levels. Athletes and individuals who sweat a lot may also be at risk. You need to carefully monitor the amount of water you drink to prevent the loss of too much potassium. Drinking water only when you are thirsty can help to naturally regulate your intake. You may also try eating more fruits and vegetables, as they are high in water content but also contain essential minerals like potassium to prevent an electrolyte imbalance.