Is this painful?
Do you have any health problems or take any medications?
Approximately how large is the area?
Thank you for responding.
Indentation like that is referred to medically as skin induration. It means that skin is becoming hardened, usually the result of some kind of inflammation or infection, cyst or tumor growth, fluid or blood accumulation.
What this ultimately means is that it is worthwhile to have it investigated to see what is literally "brewing" in that area of your shin, the most concerning reason would be an abnormal growth.
It can also occur as the result of poor blood flow, or venous stasis, but your doctor should have a look.
I hope this is helpful.
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