The thyroid gland produces hormones that influence the body's metabolism. The following symptoms can occur with an underactive thyroid:

 

• Disorders of the central nervous system with depression, forgetfulness and fatigue.

• Cardiovascular problems and low heart rate.

• Intestinal constipation and stomach problems.

• Metabolic disorders such as weight gain and hypersensitivity to cold.

• Nerve and muscle disorders such as muscle weakness.

• General complaints such as brittle nails, dry hair and dry skin.