Being tired frequently may be a sign of a thyroid disorder, but yellowing of the skin is more related to a liver or gallbladder issue rather than a thyroid problem. The thyroid gland produces a hormone called thyroxine, also known as T4, which is converted to T3 and is important in metabolism and development. The pituitary (a structure in the brain) produces TSH (thyroid stimulating hormone) which stimulates the thyroid to produce thyroxine. When these thyroid hormone levels are abnormal, then a patient can develop hypothyroidism (low thyroid level) or hyperthyroidism (high thyroid level). You should speak to your primary physician regarding your symptoms and necessary testing.
In testing for abnormal thyroid activity, a TSH level is often obtained as a screening test. However, if that is even slightly abnormal, other testing is often required including T4 and T3 levels and occasionally other hormone levels. These are all blood tests that can be drawn by your physician.
Symptoms of hyperthyroidism include heat intolerance, weight loss
, reduction in menstrual flow, increased appetite, anxiety
, heart palpitations and tremor. Symptom of hypothyroidism include fatigue, weight gain, constipation, headache
, coarse skin, menstrual disturbances, and cold intolerance.
You should follow up with your general practitioner to discuss your symptoms and need for further testing.