Muscle strain

A muscle strain or strain is an injury involving a stretched or torn muscle or tendon (tendons are fibrous cords of tissue that connect muscle to bone).

Signs and symptoms
Strain cause:
 * pain
 * muscle spasms
 * swelling
 * muscle cramps
 * trouble moving

Acute strain
Associated with a recent trauma or injury, acute strains often result from improperly lifting a heavy object or overstressing the muscles.

Chronic strain
Chronic strains are long-lasting injuries, usually cause by overuse, especially repetitive or prolonged movements of muscles and tendons, work space injuries are very common.

Prevalence
Strains commonly occur in the general population.

Symptom recognition
They are not a diagnostic symptom of ME or CFS. 

Learn more

 * Sprains and Strains - National Institute of Arthritis and Musculoskeletal and Skin Diseases
 * WebMD