Understanding Muscle Pain and Weakness in Thyroid Disease

Muscle disease, or myopathy, may occur as a result of having an underactive thyroid (hypothyroidism) or an overactive thyroid (hyperthyroidism). As a rule, muscle problems related to these concerns generally are mild and eased with prompt treatment of the thyroid disorder. That said, in less frequent scenarios, myopathy related to thyroid disease can be severe and debilitating.

By gaining a better understanding of the muscle symptoms of thyroid disease, you'll be better prepared to get to the bottom of your discomfort or weakness.

Myopathy in Thyroid Disorders

Laura Porter / Verywell

Myopathy in Hypothyroidism
  • Weakness in muscles close to the center of the body (thighs, shoulders)

  • Cramping

  • Elevated creatinine

  • Rarely, enlarged muscles (Hoffman's syndrome)

  • Rarely, breakdown of muscle tissue (rhabdomyolysis)

Myopathy in Hyperthyroidism
  • Muscle weakness

  • Issues with the muscles involved in swallowing and breathing (rare)

  • Cramping (uncommon)

  • Creatinine levels tend to be normal

Hypothyroid Myopathy

Muscle weakness, aches, and cramping are common in people with hypothyroidism.


While the weakness associated with thyroid disease can be generalized, people typically experience it in the muscles that are closest to the center of the body, such as the thighs or shoulders. This can lead to problems climbing stairs or combing your hair.

In addition to muscle symptoms, you may have an elevated creatinine kinase level, as determined by a blood test. Creatinine kinase is a muscle enzyme that increases with a muscle injury. Creatinine kinase level, however, does not necessarily link to the severity of a person's muscle pain.

Rarely, hypothyroidism can cause more severe muscle symptoms. One example is Hoffman's syndrome, in which a person develops diffuse muscle hypertrophy (enlarged muscles) leading to significant muscle stiffness, weakness, and pain.

Rhabdomyolysis (when muscle breaks down rapidly) is another rare muscular manifestation of hypothyroidism. It's often triggered by the combination of being hypothyroid and engaging in vigorous exercise or taking a statin (a cholesterol-lowering medication).


While the precise cause of hypothyroidism-induced myopathy is still unclear, some experts speculate that the thyroxine (T4) deficiency seen in hypothyroidism leads to abnormal oxidative metabolism, which ultimately causes muscle injury and impaired muscle function.


Your doctor will ask about your symptoms and do a physical examination. A blood test will be done to measure creatinine kinase. Your doctor may recommend other tests, such as an electromyography (a test that uses electrodes to detect, translate, and record the electrical signals in your muscles and nerve cells while they're active and at rest) or a muscle biopsy, to rule out other conditions, especially if your symptoms are severe.


Treatment with the thyroid hormone replacement medication Synthroid (levothyroxine) can usually improve muscle symptoms like cramps and stiffness, although this improvement may take weeks. Muscle weakness generally takes several months to resolve.

Hyperthyroid Myopathy

Muscle weakness is the signature symptom in people with hyperthyroidism. While muscle cramps and aches may occur, they are not as common as they are in myopathy related to hypothyroidism.


Due to muscle weakness, a person may have difficulty climbing stairs, rising from a chair, holding or gripping objects, or reaching their arms above their head. Rarely, in myopathy from hyperthyroidism, the muscles affected can include those that help you swallow and breathe.

The creatinine kinase level in the bloodstream is generally normal, despite the fact that there is muscle wasting. Like in hypothyroidism-induced myopathy, the level does not correlate with the severity of a person's muscle symptoms.


Like muscle disease in hypothyroidism, the "why" behind myopathy in hyperthyroidism is also unclear. It's likely that the elevated level of thyroid hormones in the body is directly contributing. More specifically, these high thyroid hormone levels may lead to increased muscle protein degradation and muscle energy use.


As with myopathy in hypothyroidism, your doctor will perform a physical examination and ask you questions related to your muscle symptoms. He or she may also order blood tests, especially a thyroid function panel, and recommend an electromyography.

Thyroid Disease Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions

Doctor Discussion Guide Old Woman


Treatment of your hyperthyroidism will generally cure the myopathy. However, it can take time to resolve—possibly up to several months—even after the thyroid is back to its normal state.

A Word From Verywell

Muscle complaints are common in thyroid disease and can generally be alleviated with normalization of your thyroid function. Coping strategies for easing muscle pain, regardless of the cause, may be useful in the meantime: massage, warm baths, and gentle exercise, for example. Supplementing with magnesium can also help muscle cramps.

Still, it's important to see your doctor if you notice new or significant muscle pain or weakness. While your thyroid may be the culprit, there are other health conditions that can cause muscle symptoms as well. 

Was this page helpful?
Article 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. Madariaga MG. Polymyositis-like syndrome in hypothyroidism: review of cases reported over the past twenty-five years. Thyroid. 2002;12(4):331-6. doi:10.1089/10507250252949478

  2. Achappa B, Madi D. Hoffmann's Syndrome- A Rare Form of Hypothyroid Myopathy. J Clin Diagn Res. 2017;11(5):OL01-OL02. doi:10.7860/JCDR/2017/21234.9913

  3. Salehi N, Agoston E, Munir I, Thompson GJ. Rhabdomyolysis in a Patient with Severe Hypothyroidism. Am J Case Rep. 2017;18:912-918. doi:10.12659/AJCR.904691

  4. Fariduddin MM, Bansal N. Hypothyroid Myopathy. StatPearls Publishing. Updated June 4, 2019.

  5. Muscular Dystrophy Association. Endocrine Myopathies - Hyperthyroid and Hypothyroid Myopathies.

  6. Chawla J. Stepwise approach to myopathy in systemic disease. Front Neurol. 2011;2:49. doi:10.3389/fneur.2011.00049

  7. Li Q, Liu Y, Zhang Q, Tian H, Li J, Li S. Myopathy in hyperthyroidism as a consequence of rapid reduction of thyroid hormone: A case report. Medicine (Baltimore). 2017;96(30):e7591. doi:10.1097/MD.0000000000007591

Additional Reading