Hypokalemia: Low Potassium Causes, Symptoms and Treatment Overview

What hypokalemia is

Hypokalemia is the medical name for a blood potassium level lower than normal. [1] MedlinePlus gives a normal range of 3.5 to 5.1 mEq/L (3.5 to 5.1 mmol/L). [1] Your own lab report shows the range it uses, and a clinician explains your result. Potassium is an electrolyte needed for cells to function; you get it through food and the kidneys keep the balance. [1] This is an established medical condition. Labels in this guide say how strong support is; Proper evidence not found means we looked and found nothing usable.

Common causes

MedlinePlus lists:

• medicines such as diuretics (water pills), and certain antibiotics at toxic levels; [1]
• diarrhea or vomiting, laxative overuse, sweating; [1]
• eating disorders such as bulimia; [1]
• chronic kidney disease and low magnesium; [1]
• genetic disorders, such as hypokalemic periodic paralysis. [1]

A low-potassium diet is not among the common causes MedlinePlus lists. [1] Its diet page also names diuretics, too many laxatives, prolonged vomiting or diarrhea, and certain kidney or adrenal gland disorders. [2] Medicine questions belong with a pharmacist; see Medication interactions.

Symptoms

Possible symptoms include constipation, a feeling of skipped heartbeats or palpitations, muscle weakness or spasms, and tingling or numbness. [1] Symptoms are not specific, so they cannot show low potassium on their own. A blood test is needed. [1]

How it is checked

A provider orders a blood test for potassium. [1] Other blood tests may check glucose, magnesium, calcium, sodium and phosphorus, and an electrocardiogram (ECG) may be done. [1]

Treatment overview (clinician-led)

• Mild cases: the provider will likely prescribe potassium supplement pills. [1]
• Severe cases: potassium may be given through a vein. [1]
• For people who need diuretics, the provider may switch to a potassium-sparing type or prescribe extra potassium. [1]
• Potassium-rich foods can help treat and prevent a low level. [1]

Treating the cause matters too. Never stop or change a prescribed medicine on your own. Over-the-counter potassium products are not a safe substitute for a diagnosis, because too much potassium is also dangerous, especially with kidney disease. [3][2] Proper evidence not found on the safety of self-treating suspected low potassium with supplements; we checked MedlinePlus, the NHS, NIDDK and PubMed.

Special situations

Older adults: the NHS says older people should not take potassium supplements unless a doctor advises them. [4] Children and pregnancy: the sources we read did not describe hypokalemia in these groups, so ask a clinician. Kidney disease can cause both low and high potassium, so levels need professional monitoring. [1][5]

Related

Potassium, Hyperkalemia, Foods high in potassium, Electrolyte imbalance.