You might have hypothyroidism (deficiency of the thyroid hormones)
if you display a number of the following symptoms:

Low basal body temperature and overall sensitivity to cold

Depression. The brain is sensitive to low levels of the thyroid hormone

Weight gain or difficulty in losing weight

Lethargy or fatigue

Dry skin and coarse, brittle hair. Fingernails may become thin and show transverse grooves

Headaches

Menstrual problems such as prolonged and heavy bleeding with a short menstrual cycle.
Infertility may also be a problem

Recurrent infections

Constipation and impaired kidney function

Loss of libido

Source: Encyclopedia of Natural Medicine by Michael Murray, N.D., and Joseph Pizzorno, N.D. (Prima).