Place urine sample here for diagnosis. [Long Joke]

A man walks into a doctor's surgery with a sore elbow. The receptionist tells him there is a one hour wait, so he sits down in the waiting area and starts looking around sheepishly and wondering whether his minor problem is worth such a wait for a diagnosis.

In the corner of the room he notices a machine that says "place urine sample here for diagnosis". Curious, the man walks over. The instructions on the machine say to place a urine sample in a recess in the machine, and it will near-instantly provide a 100% accurate diagnosis of any medical problems. The man thinks to himself "What's the worst that can happen? it's just a sore elbow", so takes a cup into the toilets and gets a sample ready. He puts it in the machine, and presses the button. The machine whirrs for a second then spits out a short receipt. The man holds it up to his face.

YOU HAVE TENNIS ELBOW.
REST THE ELBOW AND USE ICE TO REDUCE INFLAMMATION

The man is impressed, but now decides he wants to try and trick the machine.

He returns home, and gets urine samples from his cat, dog, wife and daughter. For good measure, he gets some motor oil from his car, and finally, masturbates into the cup as well.

He takes the cup of foul mixture back to the doctor's surgery and places it in the machine before pressing the button.

The machine makes R2-D2 noises for what feels like minutes, then finally spits out a long receipt.

YOUR CAT IS FINE
YOUR DOG IS FINE
YOUR WIFE HAS HERPES
YOUR DAUGHTER IS PREGNANT
YOUR ENGINE IS GOING TO BREAK
AND IF YOU WANT YOUR TENNIS ELBOW TO GET BETTER YOU SHOULD STOP MASTURBATING