Understanding the Link Between High Potassium and Health

3. Dehydration

When the body loses too much fluid—through illness, heat, or inadequate intake—it becomes harder for the kidneys to flush out excess potassium. As a result, potassium can build up in the bloodstream. In mild cases, dehydration may simply cause fatigue and dizziness, but in more severe instances, it can tip electrolyte levels into dangerous territory. Signs like dry mouth, dark urine, and low blood pressure often point to dehydration, and restoring fluid balance typically helps bring potassium levels back to normal.