Approximately 50% of people who sustain a lateral ankle sprain does not seek treatment. A recent study suggests that lateral ankle sprains left untreated results in long-term ankle instability. On the long run, an unstable ankle may develop osteoarthritis. If you had a mild ankle sprain for the first time, you will benefit from a home program to promote healing and regain the ankle stability. This type of program takes about 4 to 6 weeks. If you had a moderate to severe sprain, immobilization is recommended followed by supervised PT.