A "pulled muscle" is commonly referred to as a muscle strain, which occurs when muscle fibers are overstretched or torn. This injury can result from excessive force, improper warm-up, or sudden movements. Symptoms include localized pain, swelling, and reduced mobility. Severity can range from mild strains, where only a few fibers are affected, to severe strains, which may involve complete tears. Depending on the severity, recovery may require rest, ice, compression, and rehabilitation to restore optimal function and prevent future injuries.