Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormone. Thyroid hormones are responsible for regulating metabolism, growth and development, and many other bodily functions.

Symptoms of hypothyroidism can include:

* Fatigue

* Weight gain

* Constipation

* Dry skin

* Brittle nails

* Thinning hair

* Cold intolerance

* Heavy or irregular menstrual bleeding

* Infertility

* Depression

* Anxiety

* Difficulty concentrating

* Muscle weakness

* Joint pain

Hypothyroidism is most common in women and people over the age of 60. It is also more common in people with certain autoimmune diseases, such as type 1 diabetes and Hashimoto's thyroiditis.

Hypothyroidism is diagnosed with a blood test that measures the levels of thyroid hormones in the blood. Treatment for hypothyroidism typically involves taking thyroid hormone replacement medication.

Hypothyroidism can be a serious condition, but it is usually manageable with treatment.