Your ligaments are tough, elastic–like bands that attach to your bones and hold your joints in place. A sprain is an injury to a ligament caused by excessive stretching. The ligament can have tears in it, or it can be completely torn apart.

Of all sprains, ankle and knee sprains occur most often. Sprained ligaments swell rapidly and are painful. Generally the greater the pain, the more severe the injury. For most minor sprains, you can probably treat the injury yourself.

Follow the instructions for P.R.I.C.E.

1. Protect the injured limb from further injury by not using the joint. You can do this using anything from splints to crutches.
2. Rest the injured limb. But don’t avoid all activity. Even with an ankle sprain, you can usually still exercise other muscles to prevent deconditioning. For example, you can use an exercise bicycle, working both your arms and the uninjured leg while resting the injured ankle on another part of the bike. That way you still get three–limb exercise to keep up your cardiovascular conditioning.
3. Ice the area. Use a cold pack, a slush bath or a compression sleeve filled with cold water to help limit swelling after an injury. Try to apply ice as soon as possible after the injury. If you use ice, be careful not to use it for too long, as this could cause tissue damage.
4. Compress the area with an elastic wrap or bandage. Compressive wraps or sleeves made from elastic or neoprene are best.
5. Elevate the injured limb whenever possible to help prevent or limit swelling.

After the first two days, gently begin using the injured area. You should feel a gradual, progressive improvement. Over–the–counter pain relievers, such as ibuprofen (Advil, Motrin, others) and acetaminophen (Tylenol, others) may be helpful to manage pain during the healing process.

Get emergency medical assistance if

• You heard a popping sound when your joint was injured, you can’t use the joint, or you feel unstable when you try to bear weight on the joint. This may mean the ligament was completely torn. On the way to the doctor, apply a cold pack.
• You have a fever higher than 100 F (37.8 C), and the area is red and hot. You may have an infection.
• You have a severe sprain. Inadequate or delayed treatment may cause long–term joint instability or chronic pain.
• You aren’t improving after the first two or three days.

Source: www.mayoclinic.com