Thyroid Disorders

Was this helpful?
(18)

What are thyroid disorders?

Thyroid disorders are conditions that cause malfunctioning of the thyroid gland. The thyroid gland is located in the front part of the neck and releases hormones that regulate your metabolism and the way you use energy. Thyroid disorders can cause the thyroid gland to become underactive (hypothyroidism) or overactive (hyperthyroidism).

Hypothyroidism

Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone to properly regulate metabolism. This results in a slowing of the body’s chemical processes and metabolism. Symptoms of hypothyroidism typically include:

  • Cold intolerance

  • Constipation

  • Decreased memory and concentration

  • Depression

  • Fatigue and lack of energy

  • Hoarseness

  • Weight gain

  • Thyroid disorders that commonly cause hypothyroidism include Hashimoto’s thyroiditis and viral infections of the thyroid gland.

Hypothyroidism is also called myxedema, low thyroid, underactive thyroid, or slow thyroid. Hypothyroidism is more common in women than in men. It is also more common in people older than 50.

There is no cure for hypothyroidism. However, with diagnosis and treatment, low levels of thyroid hormone can be replaced to normal levels in the body. This normalizes your metabolism, reverses your symptoms, and minimizes the risk of complications, such as myxedema coma.

Hyperthyroidism

Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone to properly regulate metabolism. This results in a quickening or stimulation of the body’s chemical processes and metabolism. Symptoms of hyperthyroidism typically include:

Thyroid disorders that commonly cause hyperthyroidism include thyroid nodules and Graves’ disease. Hyperthyroidism is also more common in women than in men.
Prompt diagnosis and treatment of hyperthyroidism can result in a good prognosis and possibly a cure in some cases. With regular medical care and compliance with treatment, many people with the disease have an active, normal life.

In some cases, untreated thyroid disorders can lead to serious, potentially life-threatening symptoms and complications, such as birth defects, cardiac arrhythmias, heart failure, or myxedema coma. Seek immediate medical care (call 911) if you, or someone you are with, have chest pain, palpitations, confusion, change in consciousness, shortness of breath, or instances of passing out.

What are the symptoms of thyroid disorders?

Symptoms of thyroid disorders vary greatly depending on the specific disorder and if it results in hypothyroidism (underactive thyroid gland) or hyperthyroidism (overactive thyroid gland).

Symptoms of hypothyroidism

Symptoms of hypothyroidism are caused by a sluggish or slow metabolism due to a lack of thyroid hormone. The types and severity of symptoms of hypothyroidism vary between individuals. At the onset of the disease, the symptoms can be vague and progress slowly. Symptoms may include:

Later symptoms of undiagnosed or untreated hypothyroidism can include:

  • Depression

  • Slowing of speech

  • Swelling of the hands, feet, face, arms or legs

  • Thickening skin

  • Thinning eyebrows

Serious symptoms that might indicate a life-threatening condition

The following symptoms can indicate that an underactive thyroid condition is getting worse and may become a life-threatening situation. Seek immediate medical care (call 911) if you, or someone you are with, have any of the following symptoms:

  • Change in level of consciousness or alertness, such as passing out or unresponsiveness

  • Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations or delusions

  • Dizziness

  • Low blood pressure (hypotension)

  • Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, wheezing, not breathing, or choking

Symptoms of hyperthyroidism

Symptoms of hyperthyroidism are caused by an increase in metabolism due to an overproduction of thyroid hormone. Symptoms can include:

  • Anxiety and nervousness

  • Diarrhea

  • Difficulty sleeping

  • Extremely smooth skin and changes in the nails

  • Eye symptoms, such as bulging eyes, eye puffiness, light sensitivity, and an intense stare

  • Feeling overenergized

  • Goiter (swelling of the thyroid gland in the front of the neck)

  • Increased appetite

  • Increased sensitivity to heat

  • Muscle weakness and fatigue

  • Shaky hands or tremors

  • Sweating

  • Unexpected weight loss

Serious symptoms that might indicate a life-threatening condition

Hyperthyroidism can lead to serious and life-threatening complications, such as angina (chest pain), hypertension, and heart failure. Seek immediate medical care (call 911) if you, or someone you are with, have any of these symptoms:

  • Change in level of consciousness or alertness, such as passing out or unresponsiveness

  • Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations or delusions

  • Chest congestion and wet chest cough

  • Chest pain, chest tightness, chest pressure, or palpitations

  • High fever (higher than 101 degrees Fahrenheit)

  • Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, wheezing, not breathing, or choking

What causes thyroid disorders?

Thyroid disorders are often caused by an autoimmune thyroid disease, such as Graves’ disease and Hashimoto’s thyroiditis. Autoimmune thyroid diseases occur when the body’s immune system mistakes healthy thyroid tissue as potentially dangerous to the body and attacks it, causing abnormal thyroid hormone production.

Causes of hypothyroidism

Hypothyroidism occurs when the thyroid gland is underactive and produces too little thyroid hormone, which is important for normal metabolism. A decrease in thyroid hormone production can be caused by a variety of diseases and conditions. Most commonly, hypothyroidism is the result of thyroid gland inflammation, which can be due to:

  • Hashimoto’s thyroiditis, an autoimmune disease in which the body’s immune system mistakes healthy thyroid tissue as potentially dangerous to the body and attacks it. This results in inflammation of the tissue, which can eventually destroy the function of the thyroid gland.

  • Viral infection of the thyroid gland (viral thyroiditis)

Hypothyroidism can also be caused by:

  • Birth defects, such as being born without a thyroid gland or with an abnormal thyroid gland

  • Disorders of the pituitary gland or the hypothalamus, which are glands that control the function of the thyroid gland

  • Radiation treatment of the neck

  • Treatment for hyperthyroidism

Causes of hyperthyroidism

Hyperthyroidism occurs when the thyroid gland is overactive and produces too much thyroid hormone, which is important for normal metabolism. A variety of causes can stimulate the thyroid gland to make too much thyroid hormone. Causes of hyperthyroidism include:

  • Autoimmune thyroid disease (Graves’ disease), in which the thyroid gland is attacked by the body’s own immune system. This is the most common cause of hyperthyroidism.

  • Thyroid nodule, which is a noncancerous tumor that grows on the thyroid gland and produces additional thyroid hormone

  • Thyroiditis, which is inflammation of the thyroid gland (may be due to a viral infection in some cases)

What are the risk factors for thyroid disorders?

Women are generally more likely than men to develop thyroid disorders. Other risk factors vary depending on the type of thyroid disorder.

Risk factors for hypothyroidism

It is generally not possible to prevent hypothyroidism, but a number of factors can put you at risk for developing hypothyroidism. Not all people who are at risk for hypothyroidism will develop the disorder. Risk factors include:

  • Addison’s disease (chronic endocrine disorder affecting the adrenal glands)

  • Autoimmune diseases (diseases in which the body’s immune system attacks its own healthy cells and tissues)

  • Female gender, especially women older than age 50

  • Eating disorders

  • Family history of hypothyroidism

  • Gout

  • Increasing age

  • Polycystic ovary syndrome

  • Previous postpartum thyroiditis

  • Pregnancy

  • Smoking

  • Turner syndrome (female-only disorder involving a missing or incomplete sex chromosome)

Risk factors for hyperthyroidism

A number of factors increase your risk of developing hyperthyroidism. Not all people who are at risk for hyperthyroidism will develop the disorder. Risk factors include:

  • Certain common viral infections

  • Drug treatments, such as certain cancer and AIDS treatments 

  • Excessive thyroid hormone for treatment of hypothyroidism

  • Family history of Graves’ disease

  • Female gender
  • History of autoimmune diseases

  • Iodine supplements or iodine exposure

  • Recent pregnancy

  • Thyroid trauma or injury

How are thyroid disorders treated?

The treatment of thyroid disorders varies depending on the type of thyroid disorder and the underlying cause.

Treatment of hypothyroidism

There is no cure for hypothyroidism. However, with recognition and treatment, low levels of thyroid hormone can be replaced to normal levels in the body. To accomplish this, most people with hypothyroidism have to take the oral thyroid hormone replacement medication called levothyroxine for the rest of their life.

Medication therapy is closely monitored with blood tests for several months after beginning treatment to ensure you are taking the right amount of the drug. Ideal doses vary between individuals. If the dose of thyroid replacement medication is too low for an individual, it will not adequately replace thyroid hormone in the body. If the dose is too high, it may lead to hyperthyroidism and other side effects.

Once a safe and effective dose of thyroid hormone replacement medication has been established, it is then generally monitored yearly or more frequently if symptoms reappear or side effects develop. It is very important not to skip or change doses of your medication without consulting with your licensed health care provider.

Treatment of the life-threatening complication of myxedema coma may require intravenous thyroid hormone replacement medication and steroids as well as intensive monitoring in a critical care unit.

Treatment of hyperthyroidism

Hyperthyroidism is readily treated and cured in some cases. With prompt diagnosis and treatment, high levels of thyroid hormone can be returned to normal levels in the body. With regular medical care and monitoring of hyperthyroidism, many people have an active, normal life span.

Treatment of hyperthyroidism includes:

  • Beta blockers, which can minimize some symptoms, such as rapid heart rate and anxiety

  • Antithyroid medications, which decrease overproduction of thyroid hormones. In some cases, antithyroid medications may cure hyperthyroidism.

  • Regularly testing levels of thyroid hormone in the blood and adjusting, if necessary, the dosage of thyroid hormone used to treat hypothyroidism

  • Surgery to remove an overactive thyroid gland may be performed in some cases of hyperthyroidism. This may cure the disorder.

  • Swallowing of radioactive iodine, which reduces overactivity and overproduction of thyroid hormone

What are the possible complications of thyroid disorders?

Complications of untreated thyroid disorders can be serious and even life threatening in some cases. You can minimize the risk of serious complications by following the treatment plan you and your health care professional design specifically for you.

Complications of untreated hypothyroidism include:

Complications of untreated hyperthyroidism include:

Was this helpful?
(18)
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Nov 11
  1. Hyperthyroidism. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001396.
  2. Hyperthyroidism. National Endocrine and Metabolic Diseases Information Service, a service of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. http://endocrine.niddk.nih.gov/pubs/Hyperthyroidism/.
  3. Hyperthyroidism. PubMed Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001393
  4. Hypothyroidism. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/000353.htm.
  5. Bope ET, Kellerman RD (Eds.) Conn’s Current Therapy. Philadelphia: Saunders, 2013.
  6. Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.
Explore Thyroid Disorders
  • Bulging eyes are usually caused by an overactive thyroid condition like Graves’ disease. Learn the signs and symptoms of thyroid eyes and know your treatment options.
    October 23, 2020
  • If you have thyroid eye disease or Graves’ ophthalmopathy, smoking can make it worse. The good news is that quitting can improve your health and keep your eyes in better shape, too.
    October 23, 2020
  • A thyroid screening test is used to measure thyroid-stimulating hormone (TSH) levels to see if the thyroid is functioning properly. Learn more about thyroid screening guidelines, including when doctors recommend thyroid screening for newborns.
    September 17, 2020
  • Types of thyroid disorders are defined by whether the thyroid functions too little (hypothyroidism), too much (hyperthyroidism) or becomes affected by an autoimmune disorder. Learn more about how doctors approach treatment for each type of thyroid disease.
    September 17, 2020
Recommended Reading
Health Spotlight
Next Up
Answers to Your Health Questions
Trending Videos