Myalgia, or muscle pain, is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections. Longer-term myalgias may be indicative of a metabolic myopathy, some nutritional deficiencies or chronic fatigue syndrome.
The most common causes of myalgia are overuse, injury or strain. However, myalgia can also be caused by diseases, disorders, medications, or as a response to a vaccination. It is also a sign of acute rejection after heart transplant surgery.
The most common causes are:
Overuse of a muscle is using it too much, too soon and/or too often. Examples are:
The most common causes of myalgia by injury are: sprains and strains.
Multiple sclerosis (neurologic pain interpreted as muscular), Myalgic Encephalomyelitis (chronic fatigue syndrome), Myositis, Mixed connective tissue disease, Lupus erythematosus, Fibromyalgia syndrome, Familial Mediterranean fever, Polyarteritis nodosa, Devic's disease, Morphea, Sarcoidosis
Carnitine palmitoyltransferase II deficiency, Conn's syndrome, Adrenal insufficiency, Hyperthyroidism, Hypothyroidism, Diabetes, Hypogonadism, postorgasmic illness syndrome (POIS).
Chronic fatigue syndrome a.k.a. Myalgic Encephalomyelitis, Channelopathy, Ehlers Danlos Syndrome, Stickler Syndrome, Hypokalemia, Hypotonia (Low Muscle Tone), Exercise intolerance, Mastocytosis, Peripheral neuropathy, Eosinophilia myalgia syndrome, Barcoo Fever, Herpes, Hemochromatosis a.k.a. Iron Overload Disorder, Delayed onset muscle soreness, AIDS, HIV, Tumor-induced osteomalacia, Hypovitaminosis D, infarction
Withdrawal syndrome from certain drugs
Sudden cessation of high-dose corticosteroids, opioids, barbiturates, benzodiazepines, caffeine or alcohol can induce myalgia in many respects.