What could be some causes of blood slowly leaking after urination? I'm a 17 year old male and for about a year I've had a very slight pain when I urinate but it's never been too bad to concern me until now. Lately I've had horrible headaches from blood pressure rising and dropping, I also have been drinking lots of water because last week I was dehydrated after going on vacation. 

Any help or suggestions would be greatly appreciated. Thank you in advance!