What is it?

Hypokalemic periodic paralysis (hypoPP or hypoKPP) is a rare condition in which the patient has recurrent episodes of painless muscle weakness and paralysis with low potassium levels. It is more common in men and the first attack is usually between the ages 10-14. The cause for hypoPP are mutations in the genes that change the way potassium channels work, which results in low levels of potassium in the blood, needed for contraction of the muscles. There are two types for this condition; The paralytic type is the most common form in which there are intermittent, temporary episodes of muscle weakness or paralysis. The myopathy form is characterized by permanent muscle weakness, fatigue and pain. The latter form's first symptom is usually weakness or paralysis in the legs, following exercise. The episodes of hypoPP usually occur randomly but there are some known triggers such as certain foods, large meals, sleep, certain medications, temperature extremes or exercise. The length, frequency and severity of the attack vary from person to person. As the person grows older, the frequency of the attacks decreases and abortive attacks are more common- general muscle weakness lasting longer periods of time.