<unk>  <unk>  is a condition featuring attacks of muscle weakness in the presence of hyperthyroidism (overactivity of the thyroid gland). Hypokalemia (a decreased potassium level in the blood) is usually present during attacks. The condition may be life-threatening if weakness of the breathing muscles leads to respiratory failure, or if the low potassium levels lead to cardiac arrhythmias (irregularities in the heart rate). If untreated, it is typically recurrent in nature. The condition has been linked with genetic mutations in genes that code for certain ion channels that transport electrolytes (sodium and potassium) across cell membranes. The main ones are the L-type calcium channel α1-subunit and potassium inward rectifier 2.6; it is therefore classified as a channelopathy. The abnormality in the channel is thought to lead to shifts of potassium into cells, under conditions of high thyroxine (thyroid hormone) levels, usually with an additional precipitant. Treatment of the hypokalemia, followed by correction of the hyperthyroidism, leads to complete resolution of the attacks. It occurs predominantly in males of Chinese, Japanese, Vietnamese, Filipino, and Korean descent.<unk>  is one of several conditions that can cause periodic paralysis.
Thyrotoxic periodic paralysis
Hypokalemic periodic paralysis
Hyperkalemic periodic paralysis
Zaki syndrome
Thyrotoxic myopathy
Ketosis-prone diabetes
Aicardi–Goutières syndrome
Bartter syndrome