What is hypothyroidism?

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The thyroid is a gland located at the front of the neck. It is small and shaped like a butterfly. This gland produces thyroid hormones that help to regulate the body’s energy and keep the body warm. Thyroid hormones are also critical to helping organs run as they should. Changes in these hormones can affect the brain, heart, and muscles.


Hypothyroidism occurs when the thyroid gland does not make enough of the thyroid hormone. This condition can also be referred to as “underactive thyroid.” Blood tests can indicate what levels of thyroid hormones are present in a patient’s body. Without the necessary levels of thyroid hormones, many of the body’s functions will slow down, including the digestive system and heartbeat. The thyroid also controls the body’s metabolism. Hypothyroidism can slow down the chemical reactions taking place throughout the body.

What causes hypothyroidism?

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The sources of hypothyroidism vary widely. Some people have hypothyroidism due to genetic predispositions or underlying health conditions, while others develop hypothyroidism because of surgery or other medical procedures. Causes of hypothyroidism can include any of the following.

  • Hashimoto’s Disease is one of the most common causes of hypothyroidism. This autoimmune condition increases thyroid inflammation and can reduce thyroid function.
  • Thyroiditis, or the inflammation of the thyroid which can cause the thyroid to leak thyroid hormone.
  • Postpartum thyroiditis can develop after a person gives birth.
  • Hypothyroidism that is present from birth, also called congenital hypothyroidism, occurs when a baby is born with an underdeveloped or dysfunctional thyroid. Newborns are tested for hypothyroidism, as early treatment can prevent further health issues.
  • Surgery that has removed all or part of the thyroid can cause the patient to develop hypothyroidism. If only part of the thyroid has been removed, it is possible that the remaining part will produce the necessary amounts of thyroid hormones. Removing the entire thyroid will always cause hypothyroidism.
  • Thyroids that have undergone radiation treatment or chemotherapy can develop hypothyroidism. A treatment for hyperthyroidism is radioactive iodine, which destroys thyroid cells and can ultimately cause the recipient to develop hypothyroidism.
  • Some medicines can decrease thyroid hormone production, leading to hypothyroidism. Lithium (medicine for bipolar disorder), interferon alpha (medicine used to treat cancer), amiodarone (heart medicine), and interleukin-2 (medicine for kidney cancer) all carry that risk.
  • Less common causes of hypothyroidism are pituitary disease, and iodine levels that are either too high or too low.

What are symptoms of hypothyroidism?

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Some symptoms of hypothyroidism present earlier on, while others present as the condition progresses. As the body’s functions begin to slow down, various bodily outcomes could happen. Among the most common are:

  • Chills, or feeling cold
  • Weight gain
  • Slowed heart rate
  • Fatigue
  • Muscle/joint pain
  • Changes in menstruation, or difficulty with fertility
  • Decreased sweating
  • Dry skin
  • Brittle hair
  • Depression
  • Goiter
  • Muscle stiffness or tenderness
  • Constipation
  • Memory loss
  • Puffy or sensitive face

Severe hypothyroidism often presents in a life-threatening myxedema coma, which would prompt an emergency room visit. Symptoms of a myxedema coma can be identified as confusion or psychosis, loss of consciousness, accelerated fatigue or weakness, and a drop in body temperature that could cause death.

Are there any risk factors or groups for hypothyroidism?

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There are a few specific conditions that could increase a person’s chance of developing, or being born with, hypothyroidism. Two basic high-risk groups are females and people over 60 years old. However, people who fall in any of the following categories could be at increased risk for hypothyroidism.

People who have:

  • Undergone radiation treatment in chest, neck, or thyroid
  • Had a pregnancy in the last 6 months
  • Family history of thyroid problems
  • Turner syndrome, Sjogren’s syndrome, rheumatoid arthritis, Type 1 diabetes, lupus, pernicious anemia, or an autoimmune disease
  • Had a goiter or other thyroid issue before
  • Undergone surgery for thyroid issues before

As mentioned, hypothyroidism can be genetic. A patient diagnosed with hypothyroidism might encourage family members to get yearly blood testing to determine whether they have hypothyroidism as well.

What is the difference between hyperthyroidism and hypothyroidism?

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Hypothyroidism means the thyroid does not produce enough thyroid hormones, and many of its functions slow down. On the other hand, hyperthyroidism occurs when the thyroid overproduces thyroid hormones. This overproduction can result in the patient developing a voracious appetite, heat sensitivity, sudden weight loss, itchy or red skin, increased frequency of bowel movements, anxiety, shakiness, hair loss, or rapid heartbeat.


Hyperthyroidism has the opposite effect of hypothyroidism, which slows everything down. Hyperthyroidism increases hormone production and puts the body into overdrive. Patients with hyperthyroidism might even feel more energy than those with hypothyroidism. Hyperthyroidism is often caused by thyroiditis, a thyroid nodule, or Graves’ disease.


Although hypothyroidism is more common than hyperthyroidism in the United States, these conditions can be closely linked. Treatment for hyperthyroidism can actually cause hypothyroidism.

How is hypothyroidism diagnosed?

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If symptoms of hypothyroidism present in a patient, their doctor will run through the patient’s medical history and conduct a physical exam that includes several blood tests. Even after symptoms are identified, it is still difficult to immediately diagnose hypothyroidism. These symptoms can be attributed to many conditions.


Blood tests will help monitor the patient’s thyroid hormone, but the tests are specific and might not be administered in a routine physical. Thyroid blood tests could include a thyroid stimulating hormone (TSH) test, T₄ test, T₃ test, or thyroid antibody test. These tests are critical not just for a patient’s diagnosis, but also careful, often lifelong, monitoring of thyroid hormone levels.

How is hypothyroidism treated?

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Although hypothyroidism is a lifelong condition, medication can be helpful to treat symptoms.

Levothyroxine (also calledSynthroid, Levoxyl, Tirosint, or Unithroid), a synthetic T₄ hormone, mimics the hormones that the thyroid should be producing. As hormonal imbalances are repaired, symptoms will likely cease, or become less impactful.


The medication and treatment plan can take a few months to relieve symptoms. Regular blood tests and communication with a doctor will help to track the treatment plan’s progress. Right after a patient’s diagnosis, they will likely receive blood tests every 2 to 3 months. This regularity will typically decrease to once per year once the treatment plan starts to regulate the patient’s thyroid hormone levels.


Although a hypothyroidism diagnosis does not necessitate a radical diet change or restrictions, there are some considerations that could impact the thyroid’s ability to function. Some diet recommendations can be helpful for people with hypothyroidism. An iodine-balanced diet of lean proteins, whole grains, beans, fruits, and vegetables will help support the thyroid. It is possible that both soy and fiber impact the body’s ability to absorb thyroid hormones, specifically for people already on thyroid medication. Avoid taking thyroid medication with other supplements.

Should you see a doctor for hypothyroidism?

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If a patient experiences symptoms of hypothyroidism, has a family history of hypothyroidism, or receives a hypothyroidism diagnosis, they should see a doctor. Involving an endocrinologist, or someone who focuses on the thyroid, in the treatment plan is integral to the development and success of a patient’s treatment plan. Receiving the life-saving prescription of hypothyroidism medication is only possible with the involvement of a doctor. Hypothyroidism is a lifelong condition, and patients with hypothyroidism will benefit from seeing a doctor.

What is the outlook for people living with hypothyroidism?

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People living with hypothyroidism are likely to regulate their thyroid hormone production with the use of a proper treatment plan. Once diagnosed, it is probable that a patient will take thyroid hormone medication for life. That being said, a patient’s Levothyroxine dosage will change throughout their lifetime to accommodate for varying thyroid hormone levels. Doctors might also use thyroid scans, radioactive iodine uptake tests, or ultrasounds to further investigate the cause of thyroid issues. Additionally, if the patient becomes pregnant, they might need more frequent testing or a different treatment plan to monitor thyroid hormone levels.