Hypothyroidism (underactive thyroid) is a condition in which your thyroid gland doesn’t produce enough of certain crucial hormones. In the early stages, hypothyroidism may not cause noticeable symptoms. However, untreated hypothyroidism can cause a number of health problems, such as obesity, joint pain, infertility, and heart disease.

Symptoms of Hypothyroidism

  • Fatigue
  • Increased sensitivity to cold
  • Constipation
  • Dry skin
  • Weight gain
  • Puffy face
  • Hoarseness
  • Muscle weakness
  • Elevated blood cholesterol level
  • Muscle aches, tenderness and stiffness
  • Pain, stiffness or swelling in your joints
  • Heavier than normal or irregular menstrual periods
  • Thinning hair
  • Slowed heart rate
  • Depression
  • Impaired memory
  • Enlarged thyroid gland (goiter)

The signs and symptoms of hypothyroidism in adults vary, depending on the severity of the hormone deficiency. Symptoms tend to develop slowly, often over a number of years.

Causes for Hypothyroidism

Your thyroid is a small, butterfly-shaped gland situated at the base of the front of your neck, just below your Adam’s apple. Hormones produced by the thyroid gland triiodothyronine (T3) and thyroxine (T4) have an enormous impact on your health, affecting all aspects of your metabolism. These hormones also influence the control of vital functions, such as body temperature and heart rate. When your thyroid doesn’t produce enough hormones, the balance of chemical reactions in your body can be upset.

Most common causes for hypothyroidism:

  • Autoimmune disease. – The most common cause of hypothyroidism is an autoimmune disorder known as Hashimoto’s thyroiditis. Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process involves your thyroid gland.
  • Medications. – A number of medications can contribute to hypothyroidism. One such medication is lithium, which is used to treat certain psychiatric disorders. If you’re taking medication, ask your doctor about its effect on your thyroid gland.
  • Thyroid surgery. – Removing all or a large portion of your thyroid gland can diminish or halt hormone production. In that case, you’ll need to take thyroid hormone for life.
  • Radiation therapy. – Radiation used to treat cancers of the head and neck can affect your thyroid gland and may lead to hypothyroidism.
  • Over-response to hyperthyroidism treatment. – People who produce too much thyroid hormone (hyperthyroidism) are often treated with radioactive iodine or anti-thyroid medications. Sometimes, correcting hyperthyroidism can end up lowering thyroid hormone production too much, resulting in permanent hypothyroidism.

Less common causes for hyperthyroidism include:

  • Pregnancy. – Some women develop hypothyroidism during or after pregnancy (postpartum hypothyroidism), often because they produce antibodies to their own thyroid gland. If untreated, hypothyroidism increases the risk of miscarriage, premature delivery, and preeclampsia.
  • Pituitary disorder. – A relatively rare cause of hypothyroidism is the failure of the pituitary gland to produce enough thyroid-stimulating hormone (TSH) usually because of a benign tumor of the pituitary gland.
  • Iodine deficiency. – The trace mineral iodine found primarily in seafood, seaweed, plants grown in iodine-rich soil and iodized salt is essential for the production of thyroid hormones. Too little iodine can lead to hypothyroidism.
  • Congenital disease. – Some babies are born with a defective thyroid gland or no thyroid gland. In most cases, the thyroid gland didn’t develop normally for unknown reasons, but some children have an inherited form of the disorder. 

Who is at Risk of Developing Hypothyroidism

Although anyone can develop hypothyroidism, you’re at an increased risk if you are:

  • Women.
  • Over 60.
  • Have a family history of thyroid disease.
  • You have been pregnant or delivered a baby within the past six months.
  • Have an autoimmune disease, such as type 1 diabetes or celiac disease.
  • Have been treated with radioactive iodine or anti-thyroid medications.
  • Received radiation to your neck or upper chest.
  • You had thyroid surgery (partial thyroidectomy).

Complications Associated With Hypothyroidism

Untreated hypothyroidism can lead to a number of health problems such as:

  • Goiter.
  • Depression.
  • Infertility.
  • Heart problems.
  • Peripheral neuropathy.
  • Myxedema.
  • Birth defects.


Although it is believed that hypothyroidism most often affects middle-aged and older women, anyone can develop the condition. If you are experiencing any of the symptoms of hypothyroidism it is highly recommended to see your health care provider. Untreated hypothyroidism can cause many health problems and be harder to get back on track.