Hypothyroidism (underactive thyroid) is an endocrine disorder that occurs when a person’s body does not make enough thyroid hormone. The thyroid gland is located in the neck and produces thyroid hormone that controls how the body uses and stores energy.
One form of hypothyroidism is autoimmune thyroid disease, also called Hashimoto’s disease or Hashimoto's thyroiditis. Myxedema coma is a severe form of hypothyroidism.
Weight gain is a common symptom of hypothyroidism.
- For the most part, however, the weight gain in people with hypothyroidism is due to excess accumulation of salt and water.
- About 5 to 10 pounds of body weight may be attributed to the thyroid, depending on the severity of the hypothyroidism.
When hypothyroidism is treated, a small amount of weight loss, usually less than 10% of body weight, occurs and people usually return to the bodyweight they were before hypothyroidism developed. Once hypothyroidism is treated and thyroid hormone levels return to a normal range, a person’s ability to gain or lose weight is the same as in those who do not have thyroid problems.
Other symptoms of hypothyroidism may be subtle and some people may have no symptoms. In addition to weight gain, symptoms of hypothyroidism may include:
- Loss of energy
- Decreased appetite
- Cold intolerance
- Hair loss
- Dry skin
- Muscle pain
- Joint pain
- Weakness in the extremities
- Mood swings
- Forgetfulness/memory impairment
- Cognitive impairment
- Problems concentrating
- Decreased sweating
- Menstrual irregularities
- Fertility problems
- Numbness, tingling, and nerve entrapment syndromes
- Hearing loss
- Blurred vision
- Feeling of fullness in the throat
- Nail problems such as infection, vertical white ridges on the nails, nail splitting, brittle nails, slow nail growth, and nails lifting up
Symptoms of hypothyroidism more specific to Hashimoto thyroiditis include:
How Is Hypothyroidism Diagnosed?
A doctor will take a medical history and perform a physical examination, but blood tests are used to diagnose hypothyroidism.
Blood tests used to diagnose hypothyroidism include:
- Thyroid-stimulating hormone (TSH)
- Thyroxine (T4)
- Triiodothyronine (T3)
- Thyroid antibody tests
What Is the Treatment for Hypothyroidism?
There is no cure for hypothyroidism but it can be managed, and in most cases, proper treatment with thyroid replacement therapy can reverse signs and symptoms of hypothyroidism and patients can live a normal life span.
Treatment for hypothyroidism includes:
- Levothyroxine (LT4) (Synthroid, Levoxyl, Levothroid, Unithyroid) is most commonly used
- Since T4 is converted into triiodothyronine (T3) in other organs, most studies have not shown an advantage of combining T3 and T4 over using T4 alone
- Women may need higher doses of T4 during pregnancy