If you step on a nail and have not had a tetanus shot in the last five years, how soon should a person be vaccinated? 24 hours? 48 hours?

I use Nalgene bottles for about 75 percent of the water I drink each day. Therefore, I was startled to find out that there is some possibility that these bottles leach chemicals into the water. I've found conflicting opinions about the veracity of these claims on the Internet. What's the truth? Should I dump my Nalgene for glass? You have an earlier post about bottled water, but it doesn't seem to address this issue specifically, and you recommend purchasing reusable bottles like the ones that might be poisoning me. The bottles I use have #7 on the bottom in the recycle symbol.

1) This is in reference to your Missed periods Q&A. Another cause of missed or late periods is PCOS (polycystic ovary syndrome). A lot of health care providers don't seem to be aware of this syndrome. In this syndrome, missed or irregular periods are caused by unusual hormone levels, sometimes in combination with insulin intolerance. Because missed and irregular periods cause scar tissue build-up in the uterus (which may cause endometrial cancer) and may cause infertility, it is important that your readers know to ask their health care provider about this syndrome. There are obviously other symptoms and complications, but I just thought that I might mention it to you so that you might read up on it for your readers. Thank you.

2) I was recently diagnosed with polycystic ovary syndrome (PCOS). I'm only 17 and am afraid that this will affect my chance of having children. Should I worry? Also, I know birth control pills will help me regulate my period, but if I take them, will it stop the effects PCOS has on me? Like me gaining rapid weight, missed periods, and losing my hair? This is really worrying me. Can you inform me on this syndrome?

After a night out with friends, I stopped in a nearby cafe before heading home to use the restroom. Unbeknownst to me, the staff had just mopped the restroom with bleach. Usually, a clean bathroom is a welcome amenity, but this one in particular is very small (barely a water closet) with zero ventilation. Though I was in there a brief time, my eyes and nose began to burn and water, and I could not very well open the door until it was time to wash my hands. It's been well over an hour since I inhaled all that bleach, and my eyes, nose, throat, and lungs all burn. I can't taste anything, and all I can smell is bleach. My head also hurts. I've gotten a lot of fresh air and plan to go back outside shortly, but these side effects have yet to abate. Am I in danger of respiratory damage? Is there anything specific to this situation I can do to alleviate the pain and discomfort?

Thanks for your help.

I am the front man for a heavy metal band that is steadily growing in popularity. During shows, the whole band head bangs, but I seem to go a little bit harder than everyone else. Every morning after a show, I wake up with stiffness, soreness, and slight swelling of my neck and upper shoulders. Lately, I have been thinking that maybe thrashing my head around as if it isn't connected to my body is a bad idea.

My question is this: Does head banging cause any permanent injury that I should be concerned with? If so, how could I head bang differently to lessen the injury?

I was wondering if people can die from not going pee. How long can a person go without peeing and, if they cross that line, then what will happen? Also, can you get a blood infection from ignoring a bladder infection?