• You have severe pain and cannot put any weight on the injured joint.
• The injured area looks crooked or has lumps and bumps (other than swelling) that you do not see on the uninjured joint.
• You cannot move the injured joint.
• You cannot walk more than four steps without significant pain.
• Your limb buckles or gives way when you try to use the joint.
• You have numbness in any part of the injured area.
• You see redness or red streaks spreading out from the injury.
• You injure an area that has been injured several times before.
• You have pain, swelling, or redness over a bony part of your foot.
• You are in doubt about the seriousness of the injury or how to care for it.

A moderate sprain is caused by a worse, but incomplete tear of the ligament and is characterized by bruising, moderate pain, and swelling. A person with a moderate sprain usually has more difficulty putting weight on the affected joint and experiences some loss of function. An x ray may be needed to help the health care provider determine if a fracture is causing the pain and swelling.  People who have a severe sprain completely tear or rupture a ligament. Pain, swelling, and bruising are usually severe, and the patient is unable to put weight on the joint. An x ray is usually taken to rule out a broken bone. When diagnosing any sprain, the doctor will ask the patient to explain how the injury happened. He or she will examine the affected area and check its stability and its ability to move and bear weight.