What is Hypothyroidism?

Hypothyroidism is an underproduction of thyroid hormones by your thyroid gland. As a result, your body makes less energy, and your metabolism slows down. Your thyroid impacts many processes in your body that keep you healthy.

Hypothyroidism is also called underactive thyroid disease. Since the condition is based on thyroid problems, you might also hear it referred to as one of the thyroid gland diseases.


Hypothyroidism symptoms differ by age and severity. Thyroid disease symptoms often develop slowly, and you may not immediately notice them in yourself or loved ones.

General hypothyroidism symptoms:

  • Fatigue
  • Weight gain
  • Slow heartbeat
  • Hair thinning
  • Weak muscles
  • Muscle pain
  • Stiff muscles
  • Tender muscles
  • Dry skin
  • Goiter
  • Swollen joints
  • Stiff joints
  • Joint pain
  • Sensitivity to cold
  • Constipation
  • Memory problems
  • High cholesterol
  • Depression
  • Heavier menstruation
  • Irregular menstruation
  • Puffy face
  • Gravelly or croaky voice

Infant hypothyroidism symptoms:

  • Umbilical hernia
  • Yellowish eyes
  • Yellowish skin
  • Irregular breathing
  • Excessive tiredness
  • Enlarged tongue
  • Scratchy voice
  • Protruding tongue
  • Constipation
  • Reduced muscle tone

Childhood and teen hypothyroidism symptoms:

  • Slow or reduced growth.
  • Shorter body size.
  • Delayed mental development.
  • Delayed permanent teeth.

Adult hypothyroidism symptoms mirror the general signs and symptoms. Hypothyroidism can severely impact health, especially in infants. If you or a loved one experience any of these symptoms, please reach out to an endocrinologist at Baptist Health.


The main hypothyroidism causes include hyperthyroidism treatments, thyroid surgery, autoimmune disease, medications, and radiation therapy. Other possible causes might be pregnancy, pituitary disorder, iodine deficiency, or congenital disease.

Common hypothyroidism causes:

  • Hypothyroidism treatments — treating the condition with radioactive iodine can sometimes severely lower thyroid hormones and cause permanent hypothyroidism.
  • Thyroid surgery — when a surgeon extracts your thyroid gland or a big part of the gland, your body might not produce enough thyroid hormones for optimum health. In this case, you doctor may prescribe long term thyroid hormone medication.
  • Autoimmune disease — hypothyroidism is usually caused by Hashimoto's thyroiditis, an autoimmune disease.
  • Medication — some medications can play a role in the development of hypothyroidism. Please ask your doctor about any medication you take to ensure that it is safe for you.
  • Radiation therapy — radiation treatment for brain or throat cancer can sometimes cause hypothyroidism.

Other possible hypothyroidism causes:

  • Pregnancy — antibodies produced during pregnancy can lead to hypothyroidism. Hypothyroidism can negatively impact the developing fetus.
  • Pituitary gland failure — if the pituitary gland does not produce enough thyroid stimulating hormones (TSH), you might develop hypothyroidism. However, it is rare for low TSH levels to result in hypothyroidism.
  • Scarcity of Iodine — too little or too much iodine can lead to hypothyroidism.
  • Congenital disease — babies can be born with an irregular thyroid gland or no thyroid gland.

Risk Factors

Hypothyroidism can impact anyone of any age or gender. However, some individuals exhibit risk factors.

Hypothyroidism risk factors include:

  • Female gender
  • Age 60 or older
  • Autoimmune disorders
  • Radiation
  • Radioactive iodine
  • Anti-thyroid medication
  • Thyroid surgery
  • Pregnancy
  • Family history of thyroid conditions


Your doctor will likely use a TSH test to make a hypothyroidism diagnosis. The TSH test is a blood test that measures the levels of thyroid-stimulating hormones in your body. Your doctor may also perform a blood test to measure the levels of thyroxine, a thyroid hormone.

A malfunctioning thyroid usually shows reduced thyroxine and excess TSH.


The most common treatment for hypothyroidism is lifelong synthetic hormone medication. You can take this medication orally. Many people start to feel better as soon as they start hypothyroidism treatment.

The hormone medication restores healthy levels of thyroid hormones in your body. Since the dosage of medication your body needs may change over time, your doctor may schedule yearly appointments to check your TSH levels.

To ensure proper treatment:

  • Tell your doctor if you change medication brands.
  • Discuss your diet with your doctor, especially if you consume a lot of soy or fiber.
  • Talk to your doctor about any supplements or vitamins you might take.


Hypothyroidism is a chronic, treatable condition. Left untreated, the condition can cause serious health complications.

Untreated hypothyroidism complications:

  • Infertility — thyroid hormone deficiencies can impact ovulation and fertility.
  • Birth defects — when a mother with untreated hypothyroidism gives birth, the baby is at higher risk for birth defects and developmental disorders.
  • Heart problems — an underactive thyroid can cause high levels of cholesterol and greater risk for heart issues.
  • Myxedema — prolonged untreated hypothyroidism can lead to this rare, fatal condition marked by fatigue, sensitivity to cold, and unconsciousness.
  • Goiter — an enlarged thyroid gland that can impair breathing and swallowing.
  • Peripheral neuropathy — long-term untreated hypothyroidism can affect your peripheral nerves. This can cause discomfort, tingling, and numbness in your arms or legs.
  • Mental health issues — hypothyroidism can cause reduced mental ability and depression.

Next Steps with MyChart

Discover MyChart, a free patient portal that combines your Baptist Health medical records into one location. Schedule appointments, review lab results, financials, and more! If you have questions, give us a call.