What is the worst sickness you have ever had?

Think back to the time when you were the most sick. I’m not talking about when you were a baby and had chicken pox, but the earliest time you can fully remember the worst sickness you’ve ever had. Don’t include diseases, just a time when you were sick.

What did you have? How old were you at the time? How crappy did you feel? For how long were you sick? What medicine did you take and what did you do to combat it?