How long have I got

A man goes to his doctor for a complete checkup. He hasn't been feeling well and wants to find out if he's ill. After the checkup the doctor comes out with the results of the examination.

"I'm afraid I have some bad news. You're dying and you don't have much time," the doctor says.

"Oh no, that's terrible. How long have I got?" the man asks.

"10..." says the doctor.

"10? 10 what? Months? Weeks? What?!" he asks desperately.

"10...9...8...7..."