Why do some people gag when someone is vomiting?

Why is it that when a person vomits, it causes others to vomit — even when they don't have an illness causing it? Is this something triggered by the brain or is it something that happens by reflex (survival instinct) for someone to vomit since, perhaps, what the first person was eating may affect the second who vomits as well?


Will past experimentation with drugs lead to permanent brain damage?

I have a history of "experimentation" (infrequent or occasional use of ecstasy, 'shrooms, and other drugs — mostly prescription pills). I am completely sober now, but am worried about long-term damage to my brain. I used drugs infrequently (no more than three to five times for each substance), but drank regularly. How worried should I be? Is there anything I can do to combat long-term effects?


Is neck and back cracking all it's cracked up to be?

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.?


Is what I’m feeling nirvana or burn out from LSD use?

I've recently dropped acid about 5 times a week for oh... about 3 months now. I have grown mentally and spiritually in ways unimaginable. But friends tell me I am in a false reality now; this brings me off my trip although I now only trip mentally (without the drug). In your opinion, has acid hurt me or helped bring my level of consciousness to a higher level? Am I reaching a state of Nirvana or am I simply a burn out? Please answer this question... I haven't the gall to ask anyone else.


Do cosmetics containing sunscreen provide adequate sun protection?

I was thinking of buying a face powder that says it has an spf of 30. It seems convenient to have a powder sunblock since lotions make my oily face greasy. However, I was wondering if this powder will even be effective as a sunblock since I heard that some moisturizers and other products that advertise an added SPF sometimes don't have a high enough concentration of sunblocking ingredients to make it effective. I would like to know what do you think before I make my purchase.


Can cocaine make you 'dope sick'?

I have been shooting cocaine steadily for almost two months now and want to know what the difference between the physical and emotional addiction is. I am not sure if I have been experiencing withdrawals, but I feel sick a lot lately. I know shooting heroin has made me sick before. Can cocaine eventually make you dope sick as well?


When are colds contagious?

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)?


Why do my bowel movements stink so much?

I am living in a residence hall, and I never realized this until now, but my bowel movements are really smelly. It has gotten to a point where if I don't find a place to do it secretly, it becomes a great source of embarrassment. Could I be eating something that causes my bowel movements to be really smelly?