Perhaps the most common cause of muscle pain and weakness is fatigue due to overuse, but more serious conditions such as trauma and muscle strains and ruptures can lead to muscle pain and weakness as well. In most cases, muscle pain and weakness can be treated with plenty of rest, icing, compression, and elevation — known commonly as the RICE treatment — though in more severe cases, medications such as painkillers or anti-inflammatory pills may be necessary to treat the affected area. In the most severe cases, surgery may be necessary to repair a damaged muscle. This is usually only necessary when a muscle ruptures.
As muscles become tired, they tend to tighten. This tightening can lead to discomfort in the affected muscles. Muscle pain and weakness may result from overuse due to physical activity such as sports or day-to-day working routines. Tight muscles are also more likely to become injured; muscle strains occur when the tiny fibers that make up the muscles tear, resulting in pain in the affected muscle. When such an injury occurs, rest is important for allowing the muscles to heal on their own. Muscle fatigue or pain can be due to lactic acid build-up in the muscles, so drinking plenty of fluids may help alleviate some of the muscle pain and weakness.
A muscle can rupture completely due to injury or overuse as well. A muscle rupture occurs when the muscle fibers tear completely away from tendons or from muscle tissue. The muscle often balls up, and swelling and intense pain will accompany the injury. A muscle rupture can be extremely painful, and in many instances, the muscle will need to be surgically repaired. The recovery time for such an injury will be significantly longer than a muscle strain, and complete recovery will necessitate a gradual physical therapy routine that restores mobility and builds strength.
Athletes may choose to combat muscle pain and weakness by attempting to enhance his or her lactic acid threshold. The body uses glycogen as energy during exercise, and lactic acid is a by-product of spent glycogen. When lactic acid builds up in the muscles, the muscles may become sore, weak, tight, or otherwise uncomfortable. Such discomfort usually occurs after intense physical exercise, but performance during exercise may suffer due to lactic acid build-up. Professional trainers can help an athlete develop a strategic plan to enhance one's lactic acid threshold, thereby allowing the athlete to perform better for longer periods of time and avoid the muscle pain and weakness associated with lactic acid build-up.