I've seen a lot of sketchy DIY articles online over the years relating to self-administered health care, but I stumbled on one this morning that really scared me. The topic was black nails--the kind you get secondary to trauma, from a hematoma (blood blister) that builds up under the nail. It can cause pressure, and pain, and may even lift off the entire nail. This particular website was suggesting the best way to relieve the pressure and evacuate the blood was to puncture a hole in the nail...with a power drill.
For pity's sake, please don't do this.
Now, I've heard of heating a pin or needle and puncturing the nail (not recommending you do this to yourself, either), but a power drill?
The main problem I have with either of these methods is that you're never certain that the instrument you use is sterile. If bacteria is introduced into a wound (and there is a wound, since you're bleeding under there), you could end up with an infection and you'll likely lose the nail anyway. The specific problem I have with using a drill bit is that if it gets away from you, you can turn a simple black nail into an impaled toe--which comes with a whole new set of problems, obviously.
The general rule when it comes to treating these nail blood blisters is that if the black discoloration from the blood collection is less than 50% of the nail, we leave it alone. Often you don't lose the nail, and while it may grow out discolored or with ridges, keeping Mother Nature's dressing (think of the nail as a biological bandaid) intact can save you from infection.
Now, if the hematoma is bigger than 50% of the nail, we'll often remove the whole thing. Don't panic--this is not a hard and fast rule, but this is why it's a good choice: when more than 50% of the nail has been lifted by a fluid collection (in this case, blood), you often lose the nail eventually anyway. It's safer and less painful for us to remove the damaged nail cleanly and in a controlled setting rather than you having it tear off in a sock while you're rushing to get to work a week later. Nails grow back slowly, about a millimeter a month, so over the course of the next year you'll regrow a whole new nail. A very small percentage of time the nail never grows back, but that's generally in the case of a major trauma to the toe.
Last thing, and this is important: if something crushes your toe and you end up with a red, swollen, painful toe with a black nail, you should get an x-ray to make sure the small bone in the toe under the nail isn't broken. If you have a broken bone AND a nail hematoma, it's an invitation for a deep infection. If we do see a break, we generally put you on a course of antibiotics to kill any bacteria that may be in the area so they don't set up shop in the broken bone.
Moral of the story: if you've got a black nail due to recent trauma, come in, let us get an x-ray, and if the nail looks like it needs to come off, we can talk about options.
Just please don't go after yourself with a power drill!