1) I read the information on your website about knuckle cracking, and I was wondering if it applies to cracking backs and necks. I know that people often have their backs cracked by friends, etc. because it feels good and seems to relieve tension. Also, when my neck feels tight, I often turn it from side to side until it cracks and feels better. I've heard that chiropractors do some version of this, and call it "realignment." Is this safe? Is there a right or a wrong way to crack a back or neck? Is cracking your back/neck actually therapeutic in some way?

2) As a college student, I sometimes spend long hours reading books or looking at computer screens, and often my neck gets stiff. Like many of my joints that get stiff, sometimes I crack my neck, like I would crack my knees or fingers when they feel stiff. I often wind up doing this several times a day.

My question is, could I do irreparable damage to my spinal system if I continue using this method to soothe a stiff neck? Could I wind up a paraplegic if I continue to crack my neck? Leak spinal fluid, etc.?

1) Many people are buying Swarovski crystal beads to make crafts. I understand that they have 32 percent lead. People are making jewelry and figurines with the crystal beads. Is this a danger to our health?

2) We received a 24 percent leaded crystal decanter from Poland as a gift. We would like to use it for a liquor decanter. Is it safe? Are we in danger of lead poisoning?

Is there any chance that because I get low blood sugar occasionally, I may become a diabetic someday? And what can you keep with you to take when your levels do drop, and you can't get to any food or juice?

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?

1) Are wet dreams in a sexually active 23-year-old male unusual?

2) I only had about three to four "wet dreams" in my entire life and now I'm 20 years old. I wonder if it is normal, or it's because I masturbate often that I don't have these kinds of dreams. Is there a way of having one like that again?

3) I have a normal sex life with my wife (once or twice a week), but I have been having a problem lately. I have had about four wet dreams last year. I don't know why but I feel really bad about this. Is there something wrong with me? How can I stop this???

Recently I bought a sun protection cream from a health food store. The cream claims to provide sun protection (it's labeled SPF 15) by a plant complex made of PABA, willow bark extract, myrtle and myrtus leaf extract. It says that myrtle and myrtus leaf help protect from both UVA and UVB.

My questions are as follows:

1) Can this PABA complex provide the sun protection it claims (SPF 15 for both UVA and UVB rays)? The reason I am asking this is because until now I had only heard of sun protection by titanium dioxide or chemicals like octyl mexaoxycinnamate (did I get it right?). So I am curious to find out.

2) I notice a slight burning sensation in my eyes after I apply the product on my face. Is it true that PABA is a common irritant? (Since I notice many products proudly claiming PABA-free I wonder if it's really not good for you.)

Please help. I hope this question falls within your realm of expertise. After all, you are the 'know it all' around here, aren't you?

I once saw a list of plants that were helpful in cleaning air CO2 and other toxins. Do you know this list? Or, where I should look for it?

My entire life I have always talked in my sleep. According to my parents, it is just something I do. Both my parents say that it is almost impossible to sleep with me because I'm constantly kicking people, screaming, moaning, grunting, or anything else active in my sleep.

It's never been a problem for me, because I never remember doing any of it, unless I wake myself up while screaming. But now that I'm living with my fiancé it has become a problem. He's a lite sleeper and well... I'm not. So when I'm moving around I wake him up, and he never gets a full night's sleep. He's even occassionaly taken to sleeping on the couch. So I was wondering if there was any methods medically or herbal which might be able to stop my over-active sleeping patterns.

When is a person with a cold contagious? A couple of friends, who are put off when I keep my distance from their sneezing and coughing, insist one is only contagious a week or so before symptoms appear. In the back of my memory is the idea that one remains contagious until a few days *after* primary symptoms disappear. I'm not usually so concerned about this, but I'm coping with a couple of other annoying health problems and want to try to avoid adding a cold or flu, to boot. I do the usual things news shows recommend — eat well, wash hands frequently. But when should one avoid others who have colds, or when should one stay isolated at home when one has a cold (or flu)?