PATHOLOGY

Detailed explanation-1: -In general, when the thyroid hormone binds to its intranuclear receptor, it activates the genes for increasing metabolic rate and thermogenesis. Increasing metabolic rate involves increased oxygen and energy consumption. Heart: thyroid hormones have a permissive effect on catecholamines.

Detailed explanation-2: -Both hyperthyroidism and hypothyroidism can cause fatigue. In people with hyperthyroidism, the thyroid gland is overactive and makes too much thyroid hormone, which can accelerate metabolism as well as heart rate. This can lead to fatigue.

Detailed explanation-3: -The thyroid gland is a vital hormone gland: It plays a major role in the metabolism, growth and development of the human body. It helps to regulate many body functions by constantly releasing a steady amount of thyroid hormones into the bloodstream.