Myalgia is a medical term for muscle pain. It can be acute, or short-term, such as when you have sore muscles the day after exercising. Myalgia can be localized to one area of the body or groups of muscles, or it can be systemic muscle pain caused by an illness, infection, or a side effect of certain medications. The most common cause of acute myalgia is the overuse of a muscle or group of muscles, while another likely cause is viral infection, especially when there has been no trauma. Long-lasting myalgia can be caused by metabolic myopathy, some nutritional deficiencies, chronic fatigue syndrome, fibromyalgia, and amplified musculoskeletal pain syndrome.

Symptoms of myalgia can vary depending on the cause of the pain. Muscle pain may be localized or widespread, dull or sharp, mild or severe. Pain is the hallmark symptom of many chronic conditions, and it can be different and may last a few minutes or continue for hours. Myalgia can cause fevers or chills if it is caused by an infection, and it can also cause symptoms such as joint pain or fatigue.

Diagnosis of myalgia requires careful clinical evaluations of muscle cramps and joint pain. When the cause of myalgia is unknown, it should be treated symptomatically. Common treatments include heat, rest, paracetamol, NSAIDs, massage, cryotherapy, and muscle relaxants. To ease muscle pain due to overuse or injury, rest the body part and take acetaminophen or ibuprofen. Applying ice within the first 24 to 72 hours of an injury can reduce pain and inflammation. After that, heat can be more soothing. Muscle pain from overuse and fibromyalgia respond well to massage and gentle stretching exercises.

In summary, myalgia is a symptom of many diseases and can be caused by overuse, injury, strain, allergies, diseases, medications, or as a response to a vaccination. Treatment depends on the cause of the pain and can include rest, medication, and physical therapy.