Myalgia refers to muscle pain or muscle ache, which can be a symptom of several health conditions, right from the overuse of muscles or muscle injuries, to some underlying health problems. Almost everyone experience muscle aches now and then owing to physical trauma, muscle overuse, or viral infections like flu. Mild muscle pain that subsides within a day or two is usually not related to any major health problem. But muscle pain or myalgia lingering for prolonged periods of time may be associated with metabolic myopathy and conditions like chronic fatigue syndrome and fibromyalgia. The treatment or management of myalgia can differ depending on the underlying causes. But before discussing myalgia treatment or management, let's take a brief look at the factors or conditions that can cause muscle pain. As mentioned already, a wide range of factors can cause myalgia. But more commonly, it is associated with the overuse of a muscle or a group of muscles, and injuries like sprains and strains. Other than traumatic injuries, viral infections like flu or influenza can cause muscle aches, which can be accompanied by a runny nose, fever, cough, and general malaise. Muscle pain and cramps, especially nighttime muscle cramps in the legs, can be a sign of electrolyte imbalance (an imbalance of vital minerals). Minerals like calcium and potassium are essential for proper muscle functioning. The levels of these minerals can reduce in the body due to excessive sweating, vomiting, or diarrhea. Muscle weakness and a loss muscle tone can be caused by metabolic disorders like glycogen storage diseases. These are a group of inherited diseases that impair the conversion of glucose to glycogen, or the breakdown of glycogen to glucose. These diseases mostly affect the muscles and the liver, though they can affect other parts of the body, including the kidneys, heart, blood vessels, and the nervous system. Chronic fatigue syndrome is a group of medical conditions characterized by persistent and extreme fatigue that can affect the quality of life. The kind of fatigue experienced by the affected individual is not due to exertion, and is not relieved by rest. Apart from muscle pain, the affected individual can experience brain fog, impaired memory or concentration, joint pain, headaches, a sore throat, tender lymph nodes, mood swings, and irritation. What exactly causes chronic fatigue syndrome is not known, but this condition has been observed to be more prevalent in women in the age group of 40 to 50 years. Chronic muscle pain can also be associated with fibromyalgia, a condition characterized by myalgia, debilitating fatigue, sleep disturbances, numbness and tingling sensations, and joint stiffness. Though the exact causes of fibromyalgia are not known with certainty, this condition is suspected to be associated with hormonal disturbances, chemical imbalance, stress, trauma, and certain illnesses. This condition is also more prevalent in women. Sometimes, myalgia can be a symptom of malaria, dermatomyositis, polymyositis, myositis, polymyalgia, lupus disease, trichinosis, muscle abscess, rhabdomyolysis, dengue fever, polio, and HIV/AIDS. Lyme disease caused by the bacteria of the genus Borrelia, and transmitted by the bites of infected ticks, can also produce flu-like symptoms, such as muscle pain or soreness, fever, malaise, and headaches in the early stage of the infection. Sometimes, muscle pain can be caused by alcohol withdrawal or withdrawal of drugs like opioids, barbiturates, and benzodiazepines as well. Myalgia can affect muscles of the various parts of the body, and accordingly, its symptoms can vary to an extent. When it affects the muscles of the cervical region, it can cause headaches and heaviness of the head, along with muscle pain. Sometimes, it can also restrict the movement of the neck. Other symptoms that can accompany myalgia are, tingling and numbness of the affected muscle, tenderness, swelling, and redness. Myalgia is usually not caused by any major health problem, especially if the pain resolves within a day or two. But if the pain persists for more than 3 days, and is quite severe and accompanied by some other symptoms like swelling, redness, stiff neck, shortness of breath, a high grade fever, and a skin rash, it is important to seek medical attention as soon as possible. Disclaimer: This article is for informative purposes only, and should not be treated as a substitute for professional medical advice.