Originally Posted by
joypulv
Without knowing your age, weight and general health, it's hard to say online. A 'dent' should not last long at all, and it sounds like you might have slow circulation to and from your legs and possibly chronic edema.
A bruise can still press on nerves and if the blood has dried it can take a very long time to be carried away by normal process.
As we get older bruising can be very common and appear for little reason and stay for a very long time.
Try keeping your feet up, massaging your shin, soaking in warm tubs, and also walking each day to promote good circulation. If you are overweight and or smoke - much more difficult.