Hypothyroidism (underactive thyroid) is a condition in which your thyroid doesn’t create and release enough thyroid hormone into your bloodstream. This condition causes your metabolism to slow down and can affect your entire body. If left untreated, it can cause a variety of health problems such as weight gain, fatigue, heart disease and infertility.
Symptoms usually develop over time, sometimes years, depending on the severity of the hormone deficiency. As your metabolism continues to slow, you may develop more obvious problems.
Signs and symptoms may include:
Your doctor may test for an underactive thyroid if you are feeling increasingly tired, have dry skin, constipation and weight gain, or have had previous thyroid problems.
The diagnoses for this condition are based on your symptoms and results of blood tests. The blood test used is called thyroid stimulating hormone (TSH) test, which will measure the level of TSH and the level of thyroid hormone thyroxine.