Muscular pain, cramps, muscle damage and urine discoloration possible following intense exercise of brief duration. Severity varies and intense exercise should be avoided. Motor skill milestones are reached very slowly and hip displacement is not uncommon. Condition is disabling but not life-threatening. Weakness in upper arm and upper leg muscles with some evidence of wasting.
Severity depends on success in treating underlying thyroid condition.
Muscle stiffness and difficulty in moving after periods of rest. With exercise, muscle strength and movement return to normal. Condition causes discomfort throughout life but is not life-threatening. Drooping of upper eyelids, facial weakness, foot drop and some weakness of the limbs and trunk are common symptoms. Patients almost always have no reflexes.