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 breathalyzer 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."