Running is healthy for you, but it comes with complications. Because of the way you land on your heel you are at risk of ankle sprains. Running creates instability in your foot and ankle when you land. Ankle strains and sprains are quite common in the foot and ankle. Ankle sprains typically show swelling and pain even bruising at times. Sprains and strains typically have micro tears in the ligaments and/or tendons in the foot or the ankle area.
Key ways of treating this kind of injury are rest, ice, compression, and elevation. Unfortunately, following injuries such as these causes the foot to become inherently unstable. Long-term treatment of sprains and strains are use of custom orthotics, which are custom made appliances that go into your shoe gear to protect the foot and ankle from injury and long term instability.