What can a high potassium level in blood cause?

A high blood potassium level, known as hyperkalemia, can cause muscle fatigue, weakness, paralysis, nausea and heart rhythm problems, according to Mayo Clinic. In severe cases of hyperkalemia, the heart rate may become extremely slow or stop, notes MedlinePlus.

Potential causes of hyperkalemia include Addison's disease, extensive burns, severe bleeding in the digestive system, certain medications and tumors, states MedlinePlus. Uncontrolled seizures, drug and alcohol abuse, surgery, chemotherapy, and certain infections can cause muscle and cell damage that increases potassium levels. Typical treatment for hyperkalemia involves dietary modifications or medication changes. Patients who have extremely high potassium levels or are experiencing symptoms require emergency attention.