Poor Prognosis - Rob McNeill

A fellow went to his doctor for a check up  . Halfway through he asked the doctor what the prognosis was .

The doctor replied " Not good ".

The patient asked what he based that on . 

The doctor replied  "There is a problem with Mercury and Uranus ."

to which the patient replied " I didn't know you were into astrology "

The doctor said " I'm not . My thermometer broke "