Doctor's Notes on Low Potassium
(Hypokalemia)
Hypokalemia is the situation in which the blood level of potassium is abnormally low. Potassium is important for a number of body functions, and small variations in the blood level of potassium can have serious effects on the body. Nerve and muscle cells, including those in the heart, are particularly vulnerable to changes in normal potassium levels. The most common reason for low potassium levels is not a decrease in intake but rather and excessive loss of potassium through vomiting, diarrhea, laxative use, and following certain surgical procedures to remove part of the intestines. Excessive loss of potassium from the kidneys and loss due to certain medications are other reasons for hypokalemia.
Symptoms that can be associated with hypokalemia can include muscle aches, muscle weakness, or muscle cramps. Irregular heartbeats (palpitations) may also occur. Psychological symptoms like delirium, hallucinations, depression, or psychosis may accompany severe hypokalemia. In extreme cases, life-threatening complications such as cardiac arrhythmias or circulatory collapse may develop.
Low Potassium
(Hypokalemia) Symptoms
Usually symptoms of low potassium are mild. At times the effects of low potassium can be vague. There may be more than one symptom involving the gastrointestinal (GI) tract, kidneys, muscles, heart, and nerves.
- Weakness, tiredness, or cramping in arm or leg muscles, sometimes severe enough to cause inability to move arms or legs due to weakness (much like a paralysis)
- Tingling or numbness
- Nausea or vomiting
- Abdominal cramping, bloating
- Constipation
- Palpitations (feeling your heart beat irregularly)
- Passing large amounts of urine or feeling thirsty most of the time
- Fainting due to low blood pressure
- Abnormal psychological behavior: depression, psychosis, delirium, confusion, or hallucinations.
Low Potassium
(Hypokalemia) Causes
Low potassium can occur for many reasons. Use of water pills (diuretics), diarrhea, and chronic laxative abuse are the most common causes of low potassium levels.
Illness and other medications may also lower potassium levels. Woman and African-Americans are at higher risk of developing hypokalemia.
Other causes of hypokalemia include:
Kidney losses
- Certain kidney disorders such as renal tubular acidosis (for example, chronic kidney failure and acute kidney failure)
- Magnesium deficiency
- Leukemia
- Cushing's disease (and other adrenal disorders)
Loss of potassium through stomach and intestines
Effect of medicines
- Water pills (diuretics)
- Medicines used for asthma or emphysema (beta-adrenergic agonist drugs such as bronchodilators, steroids, or theophylline)
- Aminoglycosides (a type of antibiotic)
Shifting of potassium into and out of cells can lower the concentration of potassium measured in the blood.
- Use of insulin
- Certain metabolic states (such as alkalosis)
Decreased food intake or malnutrition
- Anorexia
- Bulimia
- Bariatric surgery
- Alcoholism
Food Portion Distortion : Correct Serving Size Quiz

A bagel 20 years ago was 3 inches in diameter and had 140 calories. How many calories do you think are in today's bagel?
See AnswerREFERENCE:
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.