7. Fatigue and muscle weakness
Fatigue and muscle weakness are also very important clinical signs of overactive thyroid. Of course we all feel a bit lethargic from time to time and need to rest, but fatigue begins to appear when you cannot sustain energy long enough, especially when compared to previous level of fitness.
8. Changes in menstrual patterns
Many menstrual irregularities may be symptoms of undiagnosed underlying thyroid pathology. Girls who have either very early menarche or very late menstruation should be evaluated and investigated for potential thyroid problems, as thyroid abnormalities can frequently be a cause of early or delayed menstruation and puberty.
In addition, any alteration in the menstrual patterns – such as more or less frequent menstrual periods, the onset of substantially lighter or heavier periods, or the lack of periods entirely, should suggest an underlying thyroid disease. Overactive thyroid can also cause missed periods, abnormal menstrual bleeding and in extreme circumstances infertility.