They are mentally slow and often adopt a vacant expression, and show an absence of libido. Hypothyroidism is also associated with a number of changes to the skin and subcutaneous tissues. The outer surface of the skin becomes scaly due to deterioration of sebaceous glands, and oedematous swelling occurs in the subcutaneous connective tissue, this is particularly noticeable around the face. This condition is called myxoedema . It also affects the vocal chords, deepening the voice.
Sweat glands become non-functional.
Hyperthyroidism in childhood leads to excessively tall stature and hyperactivity. Such patients commonly have chronic diarrhoea. A sign often associated with hyperthyroidism is oedematous swelling at the rear of the eye socket, causing the eyeball to bulge forward. This condition is termed exophthalmos . Hyperthyroid patients suffer from insomnia, anxiety, and tremors.