Most often, hypokalemia is asymptomatic, with no obvious signs of the disorder. However, symptoms of hypokalemia may include attacks of severe muscle weakness, eventually leading to paralysis and possibly respiratory failure.
Muscular malfunction may result in paralysis of the bowel, low blood pressure, muscle twitches and mineral deficiencies (tetany). Severe hypokalemia may also lead to disruption of skeletal muscle cells, particularly during exercise. The normal physical response to exercise requires the local release of potassium from muscle. In potassium depleted muscle, the lack of potassium prevents adequate widening of blood vessels, resulting in decreased muscle blood flow, cramps and the destruction of skeletal muscle.
Hypokalemia may also impair the ability of the kidneys to concentrate urine, resulting in excessive urination (polyuria) and excessive thirst (polydipsia). Other symptoms may include loss of appetite, nausea and vomiting. There may also be heart irregularities seen in electrocardiograph changes, confusion, distention of the abdomen, a decrease in mental activity.
Courtesy: Web MD