Whirler

Hi, I have been noticing some scalp showing on the back of my head and was wondering whether you think that it is normal or not. Also since I am 18, should I start getting some sort of medication or something or should I wait. Attached find some pics Thanks

Hi, I am worried about a small patch at the whorl in my head. I am 18 and on a relatively healthy diet. I was wondering if this is normal whorl or beginning of hairloss. Thanks