system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do doctors tell if someone, dead or alive, has been sexually abused?
gpt
Consensual sex usually involves lubrication - in a woman that lubrication comes from preparation, foreplay, and sometimes external lube. 
 
A consenting woman is more relaxed about the act of penetration, so there's a lot less chance of tearing and bruising of the vaginal tissue.  
 
A woman who does not consent to sex will struggle, and is likely to incur bruises from being held down.  Wrists, thighs, buttocks, waist, throat. 
 
Obviously, an alive victim can tell their story. A dead victim's assault is also likely to be revealed from body positioning, any missing clothing (underwear), the state of the clothing (rips), and if the victim was dressed / re-dressed properly (clothing inside out, buttons lined up improperly,) in addition to physical clues on the body.