The Link Between Thyroid Disease and Cholesterol

Thyroid disease and cholesterol levels are closely related.

Interactions between these conditions include:

  • High cholesterol (hyperlipidemia) is linked to hypothyroidism (underactive thyroid).
  • A sudden drop in cholesterol can occur with hyperthyroidism (overactive thyroid).
  • Treating thyroid disease can correct cholesterol levels.
  • Cholesterol drugs can affect thyroid disease and its treatments.

This article explains why thyroid disease and high cholesterol are linked, the potential problems, and how to manage both conditions at once.

Why Thyroid and Cholesterol Are Linked

Thyroid hormones have several jobs, including regulating your body's energy.

These hormones also control how your body uses cholesterol and other lipids (fats) and help your liver produce fatty acids, which store energy for you to use later.

When thyroid hormones are not at the right levels, these processes can be affected. Getting thyroid hormones in balance helps regulate cholesterol.

What is hypothyroidism?

Verywell / Emily Roberts


Low Thyroid & High Cholesterol

Thyroid-stimulating hormone (TSH) can be measured with a blood test. Made by a small gland in the brain called the pituitary gland, TSH stimulates your thyroid gland to release thyroid hormones.

High TSH levels usually mean you have an underactive thyroid.

Symptoms include:

  • Fatigue
  • Weight gain
  • Slow heart rate

Studies show that people with high TSH levels have much higher total cholesterol and LDL (bad cholesterol) levels than people with normal TSH levels.

Health Risks

Untreated hypothyroidism is linked to serious health risks.

These include:

High cholesterol further raises the risk of blood clots, heart disease, and stroke.

High Thyroid & Low Cholesterol

Excessively low cholesterol can cause health problems. Sometimes, a sudden drop in cholesterol levels can be a sign of an overactive thyroid.

If you have hyperthyroidism, your thyroid produces too much T3 and T4, which are thyroid hormones.

High levels of these hormones speed up certain processes in your body, leading to:

  • Anxiety
  • Sudden weight loss
  • Rapid heartbeat

Graves' disease is an autoimmune condition that causes hyperthyroidism. It sometimes involves an eye disease called orbitopathy. Increased levels of LDL and total cholesterol are risk factors for orbitopathy.

Health Risks

Without treatment, hyperthyroidism can lead to:

  • Orbitopathy
  • Osteoporosis (brittle bones)
  • Abnormal heart rhythm
  • Stroke or heart attack
  • A potentially life-threatening condition called thyroid storm

Low cholesterol is associated with an increased risk of:

  • Some cancers
  • Mood disorders
  • Heart disease

Both conditions are associated with heart disease, possibly compounding the risk.


Low thyroid activity is linked to high total and LDL cholesterol. Without treatment, an underactive thyroid could lead to heart disease, stroke, and other health issues.

High thyroid activity is linked to low cholesterol. Untreated, an overactive thyroid can lead to brittle bones, abnormal heart rhythm, and more.

Thyroid Treatment and Cholesterol

You can get effective treatment for underactive or overactive thyroid. Adequate thyroid treatment helps manage your thyroid hormones and may impact your cholesterol as well.

Underactive Thyroid Treatment

Hypothyroidism is usually treated with the drug Synthroid (levothyroxine), a synthetic form of the hormone T4. This drug often improves thyroid levels and cholesterol levels.

A large study of people with hypothyroidism and high cholesterol showed that treating the thyroid problem corrected cholesterol levels 60% of the time.

Since levothyroxine doesn't always get cholesterol levels in the ideal range, additional medical treatments may be needed.

These include cholesterol-lowering medications such as:

  • Statins, such as Lipitor (atorvastatin) or Crestor (rosuvastatin)
  • Zetia (ezetimibe)
  • PCSK9 inhibitors, such as Repatha (evolocumab) and Praluent (alirocumab)

Overactive Thyroid Treatment

Treating hyperthyroidism can help raise low cholesterol levels.

Possible treatments include:

  • Antithyroid drugs: Medications that lower your thyroid's hormone production
  • Radioiodine therapy: Comes in capsule or liquid form; slowly destroys thyroid cells that produce hormones
  • Surgery: All or part of the thyroid is removed

If your entire thyroid gland is removed, you'll need to take thyroid replacement hormones (such as levothyroxine) for the rest of your life. This is sometimes the case with partial removal and radioiodine therapy as well.


Treatment with levothyroxine can improve both an underactive thyroid and high cholesterol.

An overactive thyroid and low cholesterol can both be improved with medication, radioiodine therapy, or surgery directed at reducing the overproduction of thyroid hormone.

Cholesterol Treatments and Thyroid Disease

Cholesterol treatments can affect thyroid disease and treatment in several ways.


Drugs classified as bile acid resins may prevent your body from absorbing levothyroxine.

They're prescribed for hyperthyroidism and include:

You should take these drugs at least four hours after taking levothyroxine to avoid this effect.

Muscle Pain

Muscle pain can be a side effect of statin medications. If you have hypothyroidism, you may be likely to experience this side effect.

Hyperthyroidism Symptoms

Niacin is a treatment that is sometimes recommended for increasing HDL ("good cholesterol") levels.

Its side effects, such as flushing, can closely mimic the symptoms of hyperthyroidism. That might make you think your thyroid treatments aren't working properly.

Thyroid Eye Disease

A 2018 study found that treating high cholesterol with statin medications reduced the risk of Grave's orbitopathy.


Drugs used to lower cholesterol can produce side effects that mimic symptoms of thyroid disease and interfere with thyroid medication absorption. People who have thyroid disease may also be more likely to experience side effects of cholesterol drugs.

Lifestyle Changes for Both Conditions

Lifestyle changes can help you manage cholesterol and thyroid problems.

Your healthcare provider may recommend the following:

  • Diet: An anti-inflammatory diet may lower inflammation from autoimmune thyroid disease and lower cholesterol.
  • Weight loss: If you are overweight, sometimes weight loss can help can lower LDL cholesterol levels and improve thyroid health.
  • Exercise: Regular exercise can improve energy levels if you have hypothyroidism, and may raise your level of good cholesterol.
  • Quitting smoking: Smoking harms the thyroid and increases the risk of health complications. It also adds to the cholesterol-related risk of heart disease and stroke.


Thyroid hormones are associated with cholesterol levels. If your cholesterol is high or drops suddenly, you might need to have your thyroid checked.

Thyroid treatments may help you reduce your risk of complications such as heart attack and stroke, and they may also help you manage cholesterol.

If you are taking a cholesterol-lowering medication, know that it can affect your thyroid disease and treatments.

A Word From Verywell

Cholesterol levels can be affected by thyroid disease, and sometimes your cholesterol level can change as your thyroid condition changes and with your thyroid treatment. In addition to medication, lifestyle factors, such as diet and exercise, can have an impact as well.

25 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.
  1. Wang H, Liu A, Zhou Y, et al. The correlation between serum free thyroxine and regression of dyslipidemia in adult males: A 4.5-year prospective studyMedicine (Baltimore). 2017;96(39):e8163. doi:10.1097/MD.0000000000008163

  2. National Institutes of Health, U.S. National Library of Medicine: MedlinePlus. Hypothyroidism.

  3. Li X, Wang Y, Guan Q, Zhao J, Gao L. The lipid-lowering effect of levothyroxine in patients with subclinical hypothyroidism: A systematic review and meta-analysis of randomized controlled trialsClin Endocrinol (Oxf). 2017;87(1):1-9. doi:10.1111/cen.13338

  4. Moon S, Kong SH, Choi HS, et al. Relation of subclinical hypothyroidism is associated with cardiovascular events and all-cause mortality in adults with high cardiovascular riskAm J Cardiol. 2018;122(4):571-577. doi:10.1016/j.amjcard.2018.03.371

  5. McAninch EA, Rajan KB, Miller CH, Bianco AC. Systemic thyroid hormone status during levothyroxine therapy in hypothyroidism: A systematic review and meta-analysis [published online ahead of print, 2018 Aug 15]. J Clin Endocrinol Metab. 2018;103(12):4533-4542. doi:10.1210/jc.2018-01361

  6. National Institutes of Health, U.S. National Library of Medicine: MedlinePlus. Hyperthyroidism.

  7. Sabini E, Mazzi B, Profilo MA, et al. High serum cholesterol is a novel risk factor for Graves' orbitopathy: Results of a cross-sectional studyThyroid. 2018;28(3):386-394. doi:10.1089/thy.2017.0430

  8. Bandyopadhyay D, Qureshi A, Ghosh S, et al. Safety and efficacy of extremely low LDL-cholesterol levels and its prospects in hyperlipidemia managementJ Lipids. 2018;2018:8598054. doi:10.1155/2018/8598054

  9. Cappola AR, Desai AS, Medici M, et al. Thyroid and cardiovascular disease research agenda for enhancing knowledge, prevention, and treatment [published online ahead of print, 2019 May 13]. Circulation. 2019;10.1161/CIRCULATIONAHA.118.036859. doi:10.1161/CIRCULATIONAHA.118.036859

  10. Willard DL, Leung AM, Pearce EN. Thyroid function testing in patients with newly diagnosed hyperlipidemiaJAMA Intern Med. 2014;174(2):287-289. doi:10.1001/jamainternmed.2013.12188

  11. Johns Hopkins Medicine. High cholesterol: Prevention, treatment and research.

  12. Virili C, Antonelli A, Santaguida MG, Benvenga S, Centanni M. Gastrointestinal malabsorption of thyroxineEndocr Rev. 2019;40(1):118-136. doi:10.1210/er.2018-00168

  13. National Institutes of Health, U.S. National Library of Medicine: MedlinePlus. Levothyroxine.

  14. Parker BA, Thompson PD. Effect of statins on skeletal muscle: exercise, myopathy, and muscle outcomes [published correction appears in Exerc Sport Sci Rev. 2013 Jan;41(1):71]. Exerc Sport Sci Rev. 2012;40(4):188-194. doi:10.1097/JES.0b013e31826c169e

  15. Salehi N, Agoston E, Munir I, Thompson GJ. Rhabdomyolysis in a patient with severe hypothyroidismAm J Case Rep. 2017;18:912-918. doi:10.12659/AJCR.904691

  16. Mani P, Rohatgi A. Niacin therapy, HDL cholesterol, and cardiovascular disease: Is the HDL hypothesis defunct?Curr Atheroscler Rep. 2015;17(8):43. doi:10.1007/s11883-015-0521-x

  17. American Academy of Dermatology Association. Thyroid disease: A checklist of skin, hair, and nail changes.

  18. Abbott RD, Sadowski A, Alt AG. Efficacy of the autoimmune protocol diet as part of a multi-disciplinary, supported lifestyle intervention for Hashimoto's thyroiditisCureus. 2019;11(4):e4556. doi:10.7759/cureus.4556

  19. American Heart Association. Inflammation and heart disease.

  20. Brown JD, Buscemi J, Milsom V, Malcolm R, O'Neil PM. Effects on cardiovascular risk factors of weight losses limited to 5-10Transl Behav Med. 2016;6(3):339-346. doi:10.1007/s13142-015-0353-9

  21. Agnihothri RV, Courville AB, Linderman JD, et al. Moderate weight loss is sufficient to affect thyroid hormone homeostasis and inhibit its peripheral conversionThyroid. 2014;24(1):19-26. doi:10.1089/thy.2013.0055

  22. Cleveland Clinic. Uncontrolled thyroid: Exercise, diet risks. Updated October 31, 2013.

  23. Ruiz-Ramie JJ, Barber JL, Sarzynski MA. Effects of exercise on HDL functionalityCurr Opin Lipidol. 2019;30(1):16-23. doi:10.1097/MOL.0000000000000568

  24. Sawicka-gutaj N, Gutaj P, Sowiński J, et al. Influence of cigarette smoking on thyroid gland--an updateEndokrynol Pol. 2014;65(1):54-62. doi:10.5603/EP.2014.0008

  25. Henning RJ, Johnson GT, Coyle JP, Harbison RD. Acrolein can cause cardiovascular disease: a reviewCardiovasc Toxicol. 2017;17(3):227-236. doi:10.1007/s12012-016-9396-5

By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."