Hypothyroid Myopathy

Excerpt

Hypothyroid myopathy, observed in 30% to 80% of individuals with hypothyroidism, manifests in both congenital and acquired cases, presenting with generalized myalgias, muscle weakness, and muscle pain or stiffness. Thyroid hormone is pivotal for metabolism, growth, and organ function, thus influencing the musculoskeletal system. Severe or untreated hypothyroidism can lead to substantial muscle disease, resulting in severe functional limitations.

The symptoms of hypothyroid myopathy can be gradual in onset and nonspecific, necessitating a high index of suspicion from clinicians to differentiate this condition from fatigue and other muscle disorders with similar presentations. All patients diagnosed with hypothyroidism should be questioned about musculoskeletal symptoms. Proximal muscles, such as those in the thighs, hips, shoulders, and neck, are particularly affected, impacting activities such as stair climbing, rising from a seated position, and lifting objects. Rarely, severe hypothyroid myopathy can result in muscle necrosis, acute compartment syndrome, or respiratory failure.