A police officer pulls over this guy who's been weaving in and out of the lanes. He goes up to the guy's window and says,

"Sir, I need you to blow into this breathalyser tube".

The man says, "Sorry, officer, I can't do that. I am an asthmatic. If I do that, I'll have a really bad asthma attack".

"Okay, fine. I need you to come down to the station to give a blood sample".

"I can't do that either. I am a hemophiliac. If I do that, I'll bleed to death".

"Well, then, we need a urine sample".

"I'm sorry, officer, I can't do that either. I am also a diabetic. If I do that, I'll get really low blood sugar".

"All right, then I need you to come out here and walk this white line".

"I can't do that, officer".

"Why not?"

"Because I'm drunk".