# Myalgia

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.

## Causes

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; autoimmune diseases, such as celiac disease, systemic lupus erythematosus, Sjögren's syndrome or polymyositis; 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).
The most common causes are:
* Injury or trauma, including sprains, hematoma
* Overuse: using a muscle too much, too often, including protecting a separate injury
* Chronic tension
Muscle pain occurs with:
* Rhabdomyolysis, associated with:
** Viral
** Compression injury leading to crush syndrome
** Drug-related
*** Commonly fibrates and statins
*** Occasionally ACE inhibitors, cocaine, and some retro-viral drugs
** Severe potassium deficiency
* Fibromyalgia
* Ehlers-Danlos syndrome
* Auto-immune disorders, including:
** Mixed connective tissue disease
** Systemic lupus erythematosus
** Polymyalgia rheumatica
** Polymyositis
** Dermatomyositis
** Multiple sclerosis (this is neurologic pain localised to myotome)
* Infections, including:
** Influenza
** Lyme disease
** Babesiosis
** Malaria
** Toxoplasmosis
** Dengue fever
** Hemorrhagic fever
** Muscular abscess
** Compartment syndrome
** Polio
** Rocky Mountain spotted fever
** Trichinosis (roundworm)
** Ebola
** COVID-19
* Other
** Postorgasmic illness syndrome (POIS)

### Overuse

Overuse of a muscle is using it too much, too soon or too often. One example is repetitive strain injury. See also:
* Exercise
* Weight lifting

#### Injury

The most common causes of myalgia by injury are: sprains and strains.

### Autoimmune

* 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

### Metabolic defect

* Carnitine palmitoyltransferase II deficiency
* Conn's syndrome
* Adrenal insufficiency
* Hyperthyroidism
* Hypothyroidism
* Diabetes
* Hypogonadism
* Postorgasmic illness syndrome

### Other

* 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

### Withdrawal syndrome from certain drugs

Sudden cessation of high-dose corticosteroids, opioids, barbiturates, benzodiazepines, caffeine, or alcohol can induce myalgia.

## Treatment

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