Get emergency medical assistance if:

• You're unable to bear weight on the injured leg, the joint feels unstable or numb, or you can't use the joint. This may mean the ligament was completely torn. On the way to the doctor, apply a cold pack.
• You develop redness or red streaks that spread out from the injured area. This may mean you have an infection.
• You have pain directly over the bones of an injured joint.
• You have re-injured an area that has been injured a number of times in the past.
• You have a severe sprain. Inadequate or delayed treatment may contribute to long-term joint instability or chronic pain.