Threw my back out when I turned away from a toilet after taking a leak. Spent the next 24 hours pretty much confined to bed because I could not sit and could barely walk.
It was the day before bow hunting season and I was target practicing in the back yard. Normally you use target arrow heads for practice, but once in a while you need to shoot the actual broadheads that you will be hunting with.
So I shot the broadhead through the target and needed to unscrew the head from the arrow before pulling it out. For those unfamiliar with these arrow heads, they are just 4 very sharp razor blades, like in the picture.
There is a tool I should have used to remove to remove the head but I thought I would just unscrew it by hand.
It sliced right through my left thumb and many stitches later I had a huge bandage on my thumb, sticking out like, well, a sore thumb.
I sprayed a little camo paint on the bandage and was able to hunt anyway. Yes, I was young and beer may have been involved.
Well, I was invited at a vampire-themed party. I had a nice costume and a great make-up done a professionnal who happened to be there. I had been asked to do a couple pyrotechnic effects, in particular use some flash powder for the opening scene. Unfortunately, I forgot the fuse and detonators. So, I tried to make a makeshift fuse, putting the flash powder in an ashtray. I made sure to warn everybody not to use the ashtray and put it besides my bed to be safe.
Later on, a guy came into the room and told me to hurry up, since I was needed right now. I’m a smoker, I was smoking, you can guess what I did : I put out the cigarette in the ashtray, right in the middle of the flash powder.
I burned quite nicely my fingers. It was really painful, so for a couple hours, I kept my hand in a saucepan filled with cold water (nobody was surprised, they thought that the saucepan was part of the costume for some reason). After a while, though, it was hurting a lot despite the cold water, so someone drove me to the nearest hospital, a small one in the countryside. So, I went to the emergency room, with a remarkable vampire make-up and a copper saucepan. The nice medical staff thanked me for the comic relief, since they were generally getting road victims at this time of the night.
OD prescription pain pills; fell down flight of stairs; fractured right femur; concussion; detox; rehab
Growing up on a farm many years ago— I could probably stop right there but I remember one time I really hurt myself… My father was putting in the winter wheat which meant a flat-bed truck stacked with paper sacks of seed. We had a iron rod that we would stick in the soil and then impale the empty bags on the rod so we could burn them.
After school one day I walked out into the field to relieve my Dad and I got to the truck. I can hear the tractor so I decide to just hang out there for a while and figured he’d show up when the drills needed more seed. I notice the iron rod laying in the dirt and figured I move it to the bed of the truck so it wouldn’t get lost.
Now, there were no ashes, probably blown away, and I expected it to be warm to the touch because it had been laying in the sun. So when my pain receptors in my hand began screaming at my brain, my consciousness overruled them until I eventually realized that my hand was indeed burning.
Third degree burn and no ice. Just a water jug which I poured on the wound. I was eventually treated by a professional but some immediate ice would have certainly helped.
Moral of the story: Be careful around farms. Listen to your body.
That mosquito was driving me crazy! I kept trying to kill it, but it escaped every time. Then it alighted and I threw my hand at it hard to finally get it… and my hand went straight through the window pane that the stupid mosquito was on.
So as I was standing there with my hand dripping blood, I saw the mosquito fly away unharmed.
I’m prepared to accept JBDivmstr’s word that no alcohol was involved in his story, but as far as “Hold my beer and watch this!” stories go, lighting a whole pound of gunpowder would be quite high on the list. 
I can ‘relate’ to this one. (I didn’t include it because IMHO it was just ‘one of those things, that happen’.)
While going down the interior stairs at my house, (stairs that I had been going up and down for over 30 yrs) my right heel slipped off of the edge of the step. As I started to fall I grabbed the handrail on the left side (no handrail on the right, just a wall) and as I spun around I did a sort of hop/shuffle and that same right foot came down on the next lower step, the toes of my foot landed on the edge of that step and slid off down to the next step. It ended up ‘popping’ two slivers of bone off of my lower tibia, a fairly sizable portion (2-1/2" long x 3/8" thick) from the side and a smaller piece (1-1/4" long x 1/4" thick) from the front.
Three months with a cast up to my knee and another month and a half hobbling around with a cane.
Actually, I didn’t ask anyone to ‘hold my beer’. (I only needed one hand to hold the cigarette. ;))
I was still holding said beer when I surfaced, granted I had squeezed it so hard that there wasn’t any left in the can. 
Cut the corner of my thumb off trying to cut a piece of paper with a knife instead of getting scissors. I was about 10 and still have a good scar.
Stepped on a steel rake once. I remember seeing the approaching handle. Then it was bird noises and waves of static and fuzz until I woke up.
I was making mashed potatos with a Cuisinart immersion blender. I went to taste the potatos off the blade and accidentally turned it on. I just about cut off my finger tip and still have trouble typing.
I’ve posted this one before:
When I was in grade school we got a new dog. My brothers and sister and I were always finding new games for him to play, and one day we hit upon something new to do with his ball. He loved chasing it, and would go after it if it was thrown, or just peacefully lying there. So we started playing keep away with it. Snickers would chase after the person who had the ball, who was usually holding it in front of them them teasing him with it, trying to tear it out of their hands. We got him to the point where he was leaping mouth first as soon as he saw it.
So I get thrown the ball.
I’m holding it out in front of me at about waist height.
Snickers leaps at me, mouth open wide.
I pull the ball away right before he bites down on it.
Snickers continues his arc of travel, which terminates at my crotch.
Snickers’ jaws continue the act of trying to close on the ball.
Crunch
Standing in the bathroom with your pants around your ankles while your mother tries to put neosporin on your bleeding nutsack but can’t because she’s laughing so hard cuz our dog just chomped on it is a humbling experience.
At least you didn’t have to go to the hospital, which is exactly what I found myself thinking when my … personal massager had a battery malfunction–as in, one of the batteries kind of exploded and began leaking some kind of caustic fluid very close to some very sensitive parts of my body.
I did call poison control, and while it hurt like a bitch, it wasn’t serious enough to require medical attention. At the time, I had let my SDMB subscription lapse, and while I was still working through first aid routines I re-upped so I could tell somebody about it. Because if “watch this!” is what you say before something stupid happens, “OMG guess what I just did?” is what you say immediately after.
When the beer tells you that it’s too far to walk across the apartment to get the masking tape to cover the edge before doing that cool knife trick you learned last week, the beer is wrong.
You win the ‘falling down the stairs’ challenge… 
It wasn’t a terrible injury, or anything, but… I once burnt myself on a pair of scissors. How…special. :rolleyes:
Cut left thumb off because I turned my brain off before turning my circular saw off.
Actually got it sewed back on, doesn’t bend & has numb places but was lucky. Blood & my finger in a bag of ice did wonders for my place in the ER room, ‘Who is next?’ list…
When I was three years old, I noticed there was a space between the door and the door jam when the door was open. I wondered what would happen if I put my little finger in there. I did it just as my brother was closing the door. Lost the tip of the finger.
And 3 1/2 years ago, as I was falling down five little stairs I put my hand against the wall to grab a banister that wasn’t there. When my hand hit the wall, my wristbone literally snapped off and came to rest about threre inches below my wrist.
For being some of the smartest folks on the internet, ya’ll cannot be trusted with emersion blenders evidently.
For me, it was jumping into the ‘deep’ end of the pool which turns out, wasn’t so deep. Broke 2 toes, and had to wear heels that night as a bridesmaid.
At a friends house many years ago I was playing with a lighter and an upturned empty can of coke, filling the coke can with gas, not really thinking about what I was doing.
click…click…fwoosh!!! AAAAGGGGGHHHH!!!
Cue DH running around the room arms flailing and yelling in a decidedly non-heroic fashion.
Yes, I managed to burn myself with an empty coke can, needless to say I never did that again.