When there is too much thyroid hormone in the body, the rate at which the body uses energy increases, resulting in more frequent bowel movements, loss of body weight, and a higher body temperature.

When thyroid hormone levels are low, the body's energy use slows down, leading to less fat burning, increased weight, constipation, and tiredness.

When your body has too much thyroid hormone, it makes your heart beat faster and makes you sweat more—even when you're not exercising or stressed out.

When thyroid hormone levels are below the optimal range, the body's core metabolic processes slow down, which can result in widespread physiological dysfunction and a higher risk of death.

The thyroid gland produces hormones that influence multiple bodily functions including heart rate, body temperature, metabolism, digestion, mood, cognitive function, and sex hormone levels.