Michael Moore's battle with pneumonia

Michael Moore has been struck down with pneumonia.

The outspoken filmmaker took to his Facebook account to tell his fans he was being treated in an Intensive Care Unit at a hospital in New York City.

He wrote: "I'm writing this to all of you today from the Intensive Care Unit at a hospital in New York City.

"Unfortunately, I've come down with pneumonia. Between running all over the place lately promoting my new movie (WHERE TO INVADE NEXT).

"Plus going to Flint to help the people of my hometown, plus jumping in to support Senator Sanders, plus doing a dozen other things -- well, I read somewhere you can't burn it at both ends, and if u do, it's best not to do so in the winter nor anywhere near a place full of toxic water! (sic)"

The 61-year-old activist admitted things "didn't look good" at one point but says he is on the mend now and is ready to be discharged.

He added: "The truth is, I've actually been in the ICU since Sunday night. Let's just say things didn't look good Sunday night. But thanks to a combination of good doctors, decent hospital food and 2nd-term Obamacare, I'm doing much better the last couple of days -- so much so that I'm being discharged later today. I'm to return home and rest for the coming days. All appearances for the rest of this week have been canceled. (sic)"