In less than 5% of individuals who have an overactive thyroid gland (thyrotoxicosis), a condition known as thyrotoxic periodic paralysis (TPP) may be present. About 95% of TPP occurs in men and 5% happens in women with thyrotoxicosis. Eighty percent of cases of TPP occurs in people aged less than 40 years old.
People who has TPP may experience sudden attacks of muscle weakness when their thyroid hormone levels are still higher than normal. These episodes may be triggered by heavy exercise, fasting, or high-carbohydrate meals which results in low blood potassium level. The muscle weakness usually affects the thigh and upper arm muscles more and may sometimes be accompanied by mild muscle ache.
To confirm that a person has TPP, he or she must have:
- Thyrotoxicosis (overactive thyroid gland with high thyroid hormone levels)
- Muscle weakness that is accompanied by low blood potassium level
- Recovery of muscle weakness with treatment and normalization of the low blood potassium level
Treatment of muscle weakness in TPP is replacement of potassium either intravenously or orally. Continual consumption of potassium chloride tablets is usually not required in between attacks of muscle weakness and low blood potassium level.
\If your blood potassium level is low when you do not have muscle weakness, then other causes of low blood potassium level may be present. Attacks of TPP can be eliminated once thyroid hormone levels are restored to normal with treatment.
