ABSTRACT
Periodic paralysis (PP) is a rare hereditary disorder which is characterized by recurrent muscle weaknesses due to the mutations within Na, K or Ca ion channels. In clinical practice hypokalemia, normokalemia and hyperkalemia can all be observed. There are generally some precipitating factors such as stress, vigorous exercise and high carbohydrate food consumption which all ease the occurrence of attacks. The duration of attacks range from 2-36 hours and can be shortened by K supplementation in appropriate situations. Besides this genetic disorder, in some cases PP can be seen as a result of ungoing hyperthyroidism. During hypertyhroidism Na/K ATPase pumps are activated by high catecholamine levels which all lead to uncontrolled and excess K influx and the formation of PP. Our case is a 32 years old male who describes recurrent muscle weaknesses since adolescent years without a family history. He had had a vigorous physical exercise one day before admission to the emergency department. The weakness had started suddenly making the patient almost completely paralytic without any sensorial deficit.