What Is Postprocedural Hypothyroidism?

Postprocedural hypothyroidism, also known as postoperative hypothyroidism, is a condition characterized by low thyroid levels after thyroid surgery, including thyroidectomy (full or partial removal of the thyroid).

This article discusses the symptoms, causes, diagnosis, and treatment of postprocedural hypothyroidism.

Healthcare provider feeling the thyroid gland of a young woman.

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Symptoms of Postprocedural Hypothyroidism

Inform your healthcare provider about any of the following symptoms after thyroid surgery, since they are a sign of abnormal thyroid levels:

  • A change in energy levels
  • Menstrual cycle changes
  • Skin, hair, and nail changes
  • Appetite changes
  • Changes in bowel habits
  • Mood changes

Causes of Postprocedural Hypothyroidism

The thyroid gland is a hormone-producing organ located at the base of the neck. It is responsible for making the thyroid hormones, thyroxine and triiodothyronine, which are involved in important metabolic processes throughout the body. Problems with the thyroid gland, such as cancer, goiter (enlarged thyroid), or nodules, may require surgery to remove all or part of the thyroid gland.

Postprocedural hypothyroidism is expected after the removal of the entire thyroid gland (a total thyroidectomy) since it is the only organ that can produce thyroid hormones. People who have had their entire thyroid gland removed must take medication to replace thyroid hormones.

Thyroid hormone levels may also be low after the removal of just part of the gland (known as hemithyroidectomy or lobectomy). Low thyroid levels in this setting can be temporary or permanent. In one study of people undergoing hemithyroidectomy in South Korea, thyroid function normalized after an average of one year in 2 of 3 people with hypothyroidism.

Thyroid ablation with radioactive iodine is another therapy that causes postprocedural hypothyroidism. It is sometimes used to treat an overactive thyroid, goiter, and thyroid cancer. When used to treat thyroid cancer, postprocedural hypothyroidism is always expected.

Rates and Risk Factors for Postprocedural Hypothyroidism

The rate of postprocedural hypothyroidism after thyroidectomy depends on how much of the thyroid gland is removed. In a total thyroidectomy, the rate is 100%. In hemithyroidectomy, 20% to 30% of people will require thyroid hormone replacement medication.

Risk factors for postprocedural hypothyroidism after hemithyroidectomy include the following:

  • Presence of antithyroid antibodies
  • Lymphocytic thyroiditis
  • High thyroid stimulating hormone (TSH) and low thyroxine (T4) levels prior to surgery
  • Low amount of thyroid tissue remaining

How Is Postprocedural Hypothyroidism Diagnosed?

Hypothyroidism does not always cause symptoms, which is referred to as subclinical hypothyroidism. Thankfully, simple blood tests can reveal a diagnosis of hypothyroidism regardless of the presence of symptoms. Thyroid stimulating hormone and thyroxine blood levels are measured routinely after thyroid surgery to determine if thyroid supplementation is needed and to guide the dosing of the medication.

TSH is a hormone secreted by the pituitary gland in the brain. It tells the thyroid gland to make more thyroid hormones.

T4, also known as thyroxine, is the active form of thyroid hormone that is made by the thyroid and involved in metabolic processes throughout the body. When T4 levels are low, the pituitary gland secretes more TSH, and blood levels are elevated.

Treatment of Postprocedural Hypothyroidism

It is important that postprocedural hypothyroidism is diagnosed early to prevent complications of low thyroid levels. Fortunately, treatment of hypothyroidism is possible with medication.

Thyroid hormone replacement is available as an oral medication in pill or liquid form, and the dose is adjusted based on levels of thyroid hormones.

Complications of Postprocedural Hypothyoridism

Thyroid hormones are involved in many metabolic processes, and low thyroid hormone levels can cause many symptoms:

  • Low energy levels
  • Constipation
  • Feeling cold all of the time
  • Skin, hair, and nail changes
  • Mood changes
  • Menstrual changes

Prolonged or severe hypothyroidism can be the life-threatening condition called myxedema coma, characterized by confusion, low body temperature, low heart rate, and swelling.

After thyroid surgery, thyroid hormone levels are routinely monitored for timely treatment, and longstanding or severe hypothyroidism can be avoided.

Preventing Postprocedural Hypothyroidism

It is not always possible to prevent postprocedural hypothyroidism, since you cannot control how much of the thyroid gland needs to be removed.

However, you can prevent the serious complications of hypothyroidism after surgery. Following up with your healthcare providers, getting all recommended lab tests, and taking medications as prescribed can help you ensure that thyroid levels are in a healthy range.


Postprocedural hypothyroidism is a condition of low thyroid hormone that is not uncommon—it oftentimes is an expected consequence—of thyroid surgery. In some cases, postprocedural hypothyroidism may be temporary.

Hypothyroidism is diagnosed with blood tests. Treatment involves taking thyroid hormone replacement medication and getting occasional blood tests to monitor thyroid hormone levels.

A Word From Verywell

If you are prescribed thyroid replacement therapy, it's important to take your medication as prescribed by your healthcare provider.

Try to take it at the same time each day on an empty stomach. Always tell your healthcare provider about any other medications or supplements you are on and if you have been prescribed any new medications, since thyroid medication may not be absorbed as well when given with other medication.

If you become pregnant, your medication dose will likely need to be increased and monitored carefully.

Frequently Asked Questions

  • How long does postprocedural hypothyroidism last?

    After a total thyroidectomy, postprocedural hypothyroidism is expected indefinitely and requires thyroid hormone replacement therapy. After hemithyroidectomy, postprocedural hypothyroidism may be temporary.

  • Can you have hypothyroidism if your thyroid has been removed?

    Removal of the entire thyroid gland (total thyroidectomy) always results in hypothyroidism and requires supplementation of thyroid hormones with medication. Partial thyroid removal (hemithyroidectomy or lobectomy) can also cause hypothyroidism. Hypothyroidism after a lobectomy may be permanent or temporary. Even if thyroid levels remain normal after surgery, hypothyroidism can develop months to years after surgery.

  • What is the most common cause of postprocedural hypothyroidism?

    Postprocedural hypothyroidism is caused by removal of the thyroid gland. The less thyroid tissue that is left in the body after surgery, the more likely you are to require thyroid replacement therapy. When the total thyroid gland is removed, there is 100% chance of needing replacement therapy.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. American Thyroid Association. Thyroid surgery.

  3. Tsai SH, Chien SC, Nguyen PA, et al. Incidences of hypothyroidism associated with surgical procedures for thyroid disorders: a nationwide population-based study. Front Pharmacol. 2019;10:1378. doi:10.3389/fphar.2019.01378

  4. American Thyroid Association. Radioactive iodine.

  5. Hartl DM, Guerlain J, Breuskin I, et al. Thyroid lobectomy for low to intermediate risk differentiated thyroid cancerCancers (Basel). 2020;12(11):3282. doi:10.3390/cancers12113282

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By Angela Ryan Lee, MD
Angela Ryan Lee, MD, is board-certified in cardiovascular diseases and internal medicine. She is a fellow of the American College of Cardiology and holds board certifications from the American Society of Nuclear Cardiology and the National Board of Echocardiography. She completed undergraduate studies at the University of Virginia with a B.S. in Biology, medical school at Jefferson Medical College, and internal medicine residency and cardiovascular diseases fellowship at the George Washington University Hospital. Her professional interests include preventive cardiology, medical journalism, and health policy.