A policeman pulls over a driver for swerving in and out of lanes on the highway. He tells the guy to blow a breath into a breathalyzer.
“I can’t do that, officer.”

“Why not?”

“Because I’m an asthmatic. I could get an asthma attack if I blow into that tube.”

“Okay, we’ll just get a urine sample down at the station.”

“Can’t do that either, officer.”

“Why not?”

“Because I’m a diabetic. I could get low blood sugar if I pee in a cup.”

“Alright, we could get a blood sample.”

“Can’t do that either, officer.”

“Why not?”

“Because I’m a hemophiliac. If I give blood I could die.”

“Fine then, just walk this white line.”

“Can’t do that either, officer.”

“Why not?”

“Because I’m drunk.”