Symptoms of thyrotoxicosis
Symptoms of thyrotoxicosis are generally the same in mild and moderate cases, but they're usually more intense the more severe the thyrotoxicosis is. Signs and symptoms of mild and moderate thyrotoxicosis include: Experiencing unexplained weight loss. Having an irregular heartbeat (arrhythmia). Having a rapid heartbeat (tachycardia) — usually a heart rate higher than 100 beats per minute. Experiencing muscle weakness. Feeling shaky. Feeling nervous, anxious and/or irritable. Experiencing increased sensitivity to heat. Experiencing changes in your menstruation (period). A severe case of thyrotoxicosis is called thyroid storm, or thyroid crisis. This condition is rare and requires immediate medical attention, as it can be life-threatening. Symptoms of thyroid storm (severe thyrotoxicosis) include: Having a very rapid heartbeat. Having a high fever. Feeling very agitated and confused. Having diarrhea and feeling sick. Experiencing a loss of consciousness.