If I get hurt really sharply or suddenly, I end up passing out. This has happened once when I slammed my finger in a doorway, once when I bashed my elbow on the shower wall, once when my finger was held in an awkward, painful position, and once when I got a flu shot. Why do I pass out like this, and why do I have such low pain tolerance?

My fingernails fray and chip all the time. I have tried many different nail polishes and nail hardener but nothing helps. I've been trying to grow my nails for the past year and I just can't seem to get them to grow. My mother and older sister don't have any problems getting their nails to grow. Please give me some tips on how to make my nails grow stronger and fast.

I need to take an iron supplement and have two concerns: one, I know that many foods interfere with iron absorption. How can I maximize the absorption of any iron (and calcium) supplements? My other concern is that my GI system is very sensitive. How do I deal with constipation that often goes with iron supplements?

I have a question about mumps: I had mumps while I was thirteen-years-old. I remembered that because of embarrassment. I was afraid to tell my parents about the inflammation (swelling of the testicles) at the same time I had mumps. I did not have treatment for the swelling of my testicles due to mumps. Later, the swelling went away about the same time as my mumps. Although I still can produce semen, I am deeply disturbed whether that swelling could have hindered my fertility (i.e., no production of sperm due to the blockage of the sperm channels).

What causes fever blisters on lips and how should they be treated? Also, what is the difference between fever blisters and shingles?