Hypokalemic periodic paralysis (hypoPP) is characterized by episodes of muscle paralysis lasting from a few to 24-48 hours and associated with a fall in blood potassium levels. The disease is hypokalemic periodic paralysis (MONDO_0008223). Also known as: HKPP, HOKPP, HypoPP, Westphall disease, familial hypokalemic periodic paralysis, familial periodic paralysis (& [hypokalaemic]), hypokalemic familial periodic paralysis, periodic hypokalemic paralysis.