Potassium keeps the heart's rhythm steady, moves muscles, and helps hold blood pressure in a healthy range.
When levels slip, the first clues are easy to blame on aging or a hard week.
Federal guidance from the National Institutes of Health lists certain diuretics, chronic diarrhea, laxative misuse, and inflammatory bowel disease as leading reasons potassium can quietly drop below normal.
Adults are supposed to get 3,400 mg of potassium a day for men and 2,600 mg for women, according to the NIH Office of Dietary Supplements.
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Most Americans fall short, and the medicines used by tens of millions to control high blood pressure add to the loss.
8 warning signs
The Cleveland Clinic and StatPearls, a peer-reviewed clinical reference hosted by the National Center for Biotechnology Information, describe the same escalating pattern.
The early signs are the ones most often missed.
- Extreme tiredness and a general feeling of being unwell.
- Constipation.
- Muscle weakness and spasms.
- Muscle cramps, often in the legs.
- Tingling or numbness.
- Heart palpitations, a fluttering or extra-beat sensation.
- Excessive urination and thirst.
- Difficulty breathing and irregular heartbeat, together with severe muscle weakness that can progress to paralysis.
Normal blood potassium sits between 3.5 and 5.2 mEq/L, according to Cleveland Clinic.
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The clinical reference StatPearls classifies levels below 2.5 mmol/L as severe, with a real risk of fatal arrhythmia or respiratory muscle paralysis.
Who is most at risk
Federal guidance points to a handful of groups.
People on thiazide diuretics for high blood pressure lose potassium in the urine, per the NIH fact sheet.
Because diuretics are among the most prescribed drug classes in the country, the at-risk population is very large.
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Potassium-sparing diuretics work in the opposite direction and can raise levels instead, a distinction that also matters for readers on ACE inhibitors and other blood pressure drugs.
People with inflammatory bowel disease, meaning Crohn's disease or ulcerative colitis, lose potassium through chronic diarrhea.
The NIH lists them alongside diuretic users as being at increased risk of deficiency.
People who misuse laxatives, whether for weight control, as part of an eating disorder such as bulimia nervosa, or through routine overuse of over-the-counter products, can drop into hypokalemia quickly.
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Cleveland Clinic also names heavy sweating, vomiting, insulin, some antibiotics, and corticosteroids as contributors.
When to seek urgent care, and how it is confirmed
A simple blood test on a routine metabolic panel is enough to confirm potassium status.
Cleveland Clinic advises anyone with vomiting or diarrhea lasting more than one to two days to seek medical care right away.
The StatPearls reference flags cardiac dysrhythmia, respiratory symptoms, or signs of paralysis as reasons for immediate care.
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Anyone on a diuretic who notices new cramps, palpitations or profound fatigue should mention it at the next appointment.
Potassium can be checked with a blood draw the same day.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.