The officer walks up to the driver's side window holding a Breathalyzer and says: Good evening, Sir. We are testing drivers for drunken driving.
Driver: Oh, no problem.
Officer: Would you mind blowing into this machine?
Driver: I'm sorry. I have asthma. If I blow on that, I will run out of air.
Officer: Can you take a blood test?
Driver: No, I have anemia. If you stick a needle in me, I will bleed to death.
Officer: Well, then we need a urine sample.
Driver: I'm sorry, officer. I can't do that. I'm also a diabetic. If I do that, I will get really low blood sugar.
Officer: Then get out of your car and walk 5 yards along that white line.
Driver: I’m sorry. I can’t do that either.
Officer: Why not?
Driver: Because I’m dead drunk.