Michael Douglas cancerMichael Douglas doesn't just have throat cancer.

The actor, father, and husband of actress Catherine Zeta-Jones has stage four throat cancer -- that's the most advanced stage in a series that typically numbers one through four.

So why was he looking chipper on Letterman last night?

Because as Douglas told the talk show host, "I am head and neck ... I am above the neck, so nothing's gone down, and the expectations are good ..."

Discovered last month when the 65-year-old was suffering from ear and throat pain, it's a cancer that's categorized by malignant tumors that develop in your throat, voice box, and/or tonsils.

By stage four, it's typically metastasized or spread to other organs or throughout the body.

But the spread hasn't been too bad, Douglas says, and doctors tell him his prognosis is good.

According to the Mayo Clinic, this can be a tricky one to catch -- the symptoms of throat cancer are similar to a host of other afflictions.

In other words: hypochondriacs, back off. Your cough and sore throat do not mean you need chemotherapy. Unless you did a lot of drinking, smoking, and chewing tobacco in your youth.

And if you haven't gotten the HPV shot yet (and you're under 27), this one might send you running to the doctor: the human papilloma virus isn't just tied to cervical cancer. It can cause malignancies in the throat too. Your guess how it got there.


Image via Domain Barnyard/Flickr