Thyroid function screening test (TSH)
Thyroid function is regulated by the thyroid stimulating hormone (TSH).
Changes in TSH help in the early detection of thyroid functional disorders. An overactive thyroid may be indicated by weight loss, fatigue, feeling hot, irritability, heart palpitations or diarrhoea and an underactive thyroid by weight gain, sleepiness, feeling cold or constipation. A decrease of TSH most often indicates hyperthyroidism and an increase indicates hypothyroidism; additional tests are necessary for specification.