Low potassium, known as hypokalemia, occurs when blood potassium levels drop below the normal range of 3.6 to 5.2 millimoles per liter, according to Mayo Clinic. Potential causes include diarrhea or vomiting, profuse sweating, folic acid deficiency, excessive alcohol consumption, and the use of diuretics or laxatives.
Symptoms of low potassium include constipation, fatigue, muscle weakness, tingling and numbness, states MedlinePlus. Low potassium also affects the heart by causing abnormal heart rhythms or palpitations. If the potassium levels continue to drop, the heart may slow or stop completely.
Oral or IV potassium raises the levels in the bloodstream back to a normal range, notes MedlinePlus. People who are prone to low potassium due to medication use or medical conditions can increase potassium intake through diet. Avocados, bananas, lean beef, baked potatoes and salmon are a few foods that are high in potassium.