Although a high blood potassium level usually does not produce symptoms or side effects, it may cause nausea and slow, weak or irregular pulse, according to MedlinePlus. In severe cases, the heart may stop. Muscle fatigue, weakness and paralysis can also occur, notes Mayo Clinic.
Patients who have a very high potassium level or are experiencing symptoms typically require emergency treatment to lower their potassium, explains MedlinePlus. Depending on the cause, treatment may include water pills, sodium bicarbonate or medication that prevents the intestines from absorbing potassium. Intravenous medications, such as glucose and insulin, may also be administered to lower potassium levels. Intravenous calcium can be given to patients who are experiencing side effects involving the heart or the muscles. Patients with decreased kidney function sometimes require dialysis.
Limiting foods that are high in potassium, including avocados, bananas, oranges, potatoes, tomatoes and cooked spinach, can help prevent high potassium levels in the blood. Potential causes of high potassium include Addison's disease, extensive burns, certain conditions that cause blood cells to burst, severe bleeding in the stomach and intestines, and some medications, states MedlinePlus. Activities that cause damage to the muscles and other cells, such as drug or alcohol abuse, untreated seizures, surgery, chemotherapy or certain types of infection, can also raise potassium levels.