You should seek medical attention if you are concerned about your pain. Your doctor may refer you to a rehabilitation professional to help get your strength back as quickly as possible. This plan will likely include stretch and strengthening exercises specific to the injury.
Your doctor will likely ask you about your medical history and then give you a physical exam. He or she may observe your muscles and joints, ask you to sit, lie down and move your body in different positions and check what brings the most pain. If your doctor can identify the cause of your pain after this examination, no further tests may be needed.
That depends on the severity and type of injury. Regular muscle strains could take days or weeks to fully heal. More severe injuries can take months to feel better.