Thyroid disease is several times more common in women, and its symptoms closely mirror perimenopause, iron deficiency and depression. One blood test usually separates them.
Fatigue, weight gain, cold intolerance, constipation, dry skin, hair thinning, low mood, slowed thinking, heavier periods, muscle aches, facial puffiness and reduced fertility.
Weight loss with normal appetite, heat intolerance, palpitations, anxiety, tremor, difficulty sleeping, loose stools, lighter or absent periods, muscle weakness and eye symptoms in Graves' disease.
The symptoms belong to several conditions at once, and autoimmune thyroid disease often appears after pregnancy and in the forties, when exhaustion is easy to explain away.
TSH with free T4 first line, thyroid antibodies where autoimmune disease is suspected, and full blood count with ferritin when periods are heavy. Recheck six to eight weeks after any dose change.
A fast or irregular heartbeat with chest pain or fainting, a rapidly growing neck lump, difficulty swallowing or breathing, sudden vision change, or confusion and drowsiness.