Basically, some version of the common cold, without the free-flowing sinuses but with a double-order of body and joint aches. (Aches that feel like the joint in question has been jabbed with a needle. This is especially painful in fingers and toes.)
Treatment is rest, plenty of fluids, prescription cough syrup as needed, OTC painkillers likewise. They listened carefully to my lungs and did a chest x-ray, both of which came up clear.
This would be very comforting indeed, were it not for my co-worker's pneumonia having started the same way. However, he didn't get rest when told to and "pneumonia" is a condition there are many paths to acquiring rather than a single disease.* So I am darned well going to do just what the doctor said to do. I picked up some nice (Panera Bread) drive-through food on the way home, ate it and went to bed, where I have slept for most of the last four and a half hours.
Up now, enjoying a dish of ice cream and a tall glass of water, then back to bed for awhile. I still feel like a bad job of embalming but not quite as much like someone has been hitting me and poking me with sharp things.
A few people have remarked on various backchannels, "You sure get sick a lot." Yes. Yes, I do. I work in a building where about half the employees are travelling all over and interacting with every level of society...and then coming back to the office and using the same coffee machine, copier, washroom, etc. as the rest of us. I'm kind of susceptible to colds and flu. Have been all my life; I routinely fell ill on family vacations, usually with some form of strep throat, which is the main reason I despise travel. I get flu shots every year, and most of the other vaccines old people are supposed to get, and I am careful about handwashing and hygiene or I'd be a lot sicker, a lot more often. If the current bug is related to what my coworker with pneumonia has, he's generally as healthy as an ox (which is why he kept on working as he felt worse and worse) and it took him right down; I had figured it was just about inevitably going to get me and perhaps it has.
* "Pneumonia" just describes fluid build-up in the lungs. Viruses and bacteria can cause that -- getting food down your windpipe too often can, too. There's a vaccine, which I believe immunizes against the most common bacterial cause, but the others can still get you.
4 months ago