Professor, excuse me, but I need to leave early.
What seems to be the problem?
I am not feeling well.
What is bothering you?
I think I am beginning to have an asthma attack.
Would you like someone to walk you over to the Student Health Center?
No, I think that I should just go home because I have some medicine there.
Do you need a ride home?
I live in the dorms across the street, so I'll be OK.
OK, then, hope you feel better soon. Check your e-mail for missed assignments.