Myalgia
Other names	Muscle pain, muscle ache
One of the myalgic symptoms
Specialty	Rheumatology

Myalgia or muscle pain is a painful sensation evolving from muscle tissue. It is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, especially when there has been no injury.

Long-lasting myalgia can be caused by metabolic myopathy, some nutritional deficiencies, ME/CFS, fibromyalgia, and amplified musculoskeletal pain syndrome.

The most common causes of myalgia are overuse, injury, and strain. Myalgia might also be caused by allergies, diseases, medications, or as a response to a vaccination. Dehydration at times results in muscle pain as well, especially for people involved in extensive physical activities such as workout.

Muscle pain is also a common symptom in a variety of diseases, including infectious diseases, such as influenza, muscle abscesses, Lyme disease, malaria, trichinosis or poliomyelitis;^[1] autoimmune diseases, such as celiac disease, systemic lupus erythematosus, Sjögren's syndrome or polymyositis;^[1][2] gastrointestinal diseases, such as non-celiac gluten sensitivity (which can also occur without digestive symptoms) and inflammatory bowel disease (including Crohn's disease and ulcerative colitis).^[3]

The most common causes are:^{[citation needed][4][5] [6]}

Overuse of a muscle is using it too much, too soon or too often.^[10] One example is repetitive strain injury. See also:

• Exercise
• Weight lifting

The most common causes of myalgia by injury are: sprains and strains.^[10]

• Multiple sclerosis (neurologic pain interpreted as muscular)
• 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^[7][8][9]

• Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
• Channelopathy
• Ehlers Danlos Syndrome
• Stickler Syndrome
• Hypokalemia
• Hypotonia
• Exercise intolerance
• Mastocytosis
• Peripheral neuropathy
• Eosinophilia myalgia syndrome
• Barcoo Fever
• Herpes
• Hemochromatosis
• Delayed onset muscle soreness
• HIV/AIDS
• Generalized anxiety disorder
• Tumor-induced osteomalacia
• Hypovitaminosis D
• Infarction^[11]

Sudden cessation of high-dose corticosteroids, opioids, barbiturates, benzodiazepines, caffeine, or alcohol can induce myalgia.^{[citation needed]}

When the cause of myalgia is unknown, it should be treated symptomatically. Common treatments include heat, rest, paracetamol, NSAIDs, massage, cryotherapy and muscle relaxants.^[12]

• Arthralgia
• Myopathy
• Myositis