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From heart rate to digestion to the loss of eyebrow hair, the thyroid gland affects every body system. One area that’s significantly impacted -- but often overlooked -- is the musculoskeletal system. Read on as we explore a muscle condition known as hypothyroid myopathy, its common symptoms, and treatment options.
Roughly 30% to 80% of patients with hypothyroidism develop myopathy. Myopathy is defined as a muscle disease characterized by muscle weakness. Hypothyroid myopathy is caused by a deficiency in thyroid hormone production, otherwise known as hypothyroidism.
Most commonly, hypothyroid myopathy is a result of uncontrolled or untreated hypothyroidism. The most common myopathic symptoms include slowed reflexes and proximal muscle weakness in and around the hips, especially the pelvis. Some people experience shoulder weakness and muscle symptoms such as stiffness or painful muscle cramps, especially after exercise or physical activity. People with hypothyroid myopathy may notice difficulty performing everyday activities such as climbing stairs, getting up from a squatting position, and combing their hair. In more severe and unmonitored cases, the disease can cause muscle enlargement, known as hypertrophy.
There are four unique subtypes of hypothyroid myopathy:
- Myasthenic Syndrome: A severe weakness that begins in childhood and can progress to a loss of mobility in adulthood and later life.
- Atrophic Form: This is a more severe muscle atrophy that sometimes develops in hypothyroid patients.
- Kocher Debre Semelaigne Syndrome: Also known as muscular pseudohypertrophy hypothyroidism, this rare disease is generally seen in childhood. It’s associated with muscle hypertrophy (an increase or growth of muscle cells), short stature (when a child’s height is below that of the shortest 3 to 5% of children the same age and sex), and cretinism (untreated congenital hypothyroidism).
- Hoffman Syndrome: Hoffman Syndrome (HS) is a rare condition usually seen in adults and characterized by weak, enlarged muscles (pseudohypertrophy), painful spasms, muscle weakness, and stiffness. The cause is complex, and the muscles commonly affected include the tongue, arms, and legs.
Myopathy rarely presents as a primary symptom for those with hypothyroidism. Instead, it presents with other symptoms of undiagnosed and untreated hypothyroidism or poorly treated hypothyroidism. The good news, however, is that when hypothyroidism is well treated, the symptoms of myopathy usually subside.
Prolonging optimal treatment of hypothyroidism can make treating hypothyroid myopathy more extraneous and challenging. One case study examined a 30-year-old man diagnosed after two years of hypothyroidism symptoms. He went on to normalize his thyroid function on thyroid hormone replacement therapy. However, because he went so long without diagnosis and treatment, the symptoms of myopathy did not improve quickly. Another case study of a 28-year-old woman demonstrated steady improvement in her myopathy symptoms and muscle strength while receiving therapy with levothyroxine for her hypothyroidism. These two cases reiterate the importance of early diagnosis and treatment.
If you are being treated for hypothyroidism and experiencing mild myopathy symptoms, other therapies can offer additional relief. Specifically, physical therapy and recreational physical activity can help alleviate muscular discomfort. In addition, early intervention with gentle, low-impact aerobic exercise such as walking, swimming, and biking may increase muscle efficiency and cardiovascular performance.
The most important takeaways: untreated hypothyroidism is a risk factor for hypothyroidism myopathy, and early diagnosis of hypothyroidism along with optimal and successful treatment are the keys to successful resolution of hypothyroid-induced myopathy.
Regular, accurate thyroid testing is one of the critical aspects of good hypothyroidism care. The Paloma Complete Thyroid Test kit makes thyroid testing -- including TSH, Free T4, Free T3, and Thyroid Peroxidase Antibodies (TPOAb) easy, convenient, and affordable.
And, if you need a diagnosis, management, and optimal treatment of your hypothyroidism, look to Paloma’s nationwide team of top thyroid doctors. Paloma’s thyroid-savvy doctors will work with you to develop an effective treatment program, including the best thyroid medication that can safely normalize your thyroid function and best resolve your symptoms.