I just found out that a friend requires a kidney transplant. I've heard that we are all equipped with two kidneys and can live with just one. How do I find out if I can donate a kidney? What's involved in a kidney donation? Thanks!

About six months ago, I experienced pain when urinating after having intercourse. Typically, I have pain/burning the first time I urinate after sex, but then the pain tends to go away or diminish. I am a 38-year-old male. I have no pain otherwise.

The muscles in my back become extremely tense/tight throughout the term as I am cramped down studying all the time. What should I do?

I have trouble following spoken speech. It's always made school difficult for me and now it's one of the reasons why I think I'll have to quit college (I'm on leave right now). I would listen to lectures or go to instructors for extra help, but my brain just wouldn't absorb anything it heard. This put a huge burden of self-instruction on me and it made it impossible for me to participate in class discussions.

I think this tendency affects me in other ways too. For example, I don't and never have been able to sit through movies or watch TV — I never know what's going on in them. In daily interactions I manage OK with processing short exchanges of information or instructions, but I don't have "conversations" at all unless it's absolutely necessary, and when I do it's exhausting and unpleasant (I speak VERY little and have never had a friend, so it's no exaggeration to say that I don't have conversations).

Until college, I was always able to compensate for this difficulty by just studying hard and teaching myself. I got high grades and was going to a reputedly good college. Can you suggest any explanation for a problem of this sort and how to deal with it so that I might be able to graduate from college?

I was hoping you could answer a question for me about birth control pills. There is a history of breast cancer in my family (my mother). Is it true that because of this, it is unsafe for me to use birth control pills? A few friends have recently had condoms break during sex, and I am looking for a type of "backup" contraception system.

Do men need to cover up their testicles when using indoor tanning facilities?

I use tanning booths regularly and I normally use only eye protection. I am slightly worried, however, that the UV radiation from the sunlamps could do internal damage to a man's testicles, because the skin is obviously only very thin and might not offer much protection against UV radiation. Since eyelids are similarly thin and it is known that eye damage can result even when using tanning equipment with closed eyes, I wonder if advice should be given to men to use similar precautions to prevent testicles being exposed to high-intensity UV-A or UV-B radiation. I have looked everywhere for scientific information on this matter but could not find anything. Your advice on this matter would therefore be very much appreciated.