I frequently hear that beverages with caffeine or alcohol are not good for replenishing fluids and preventing dehydration. But in reality aren't they just a bit less effective at hydrating your body than other beverages? In other words, if you were stuck in the desert with nothing to drink but beer, coffee and cola, would you actually be worse off and die of thirst sooner if you drank these beverages versus not drinking anything at all?

Do any alcohols have any specific benefits? As in, is tequila better than vodka? And is red wine the best choice because of its antioxidants?

1) I have had acid coming up my throat from my stomach for the last 3 weeks. It comes up and just burns my throat. What is it? Do I have an ulcer? By the way, I get 3 hours of sleep a night, and my roommate doesn't help the situation.

2) I have recently asked you about my would be ulcer. I shall pose the question again. Lately I have this damn acid coming up my throat. I've been under a lot of stress and have strange sleeping habits. I am also drinking a lot of coffee. I drink about 5 cups of coffee a day and my roommate isn't exactly stress relieving. I go to bed about 3:30am and wake up about 5:45am for crew. Am I dying? Do I have an ulcer? What's wrong with me?

My friends take Pepcid AC when they drink to reduce the redness on their faces. Is this safe? I'm worried that it will hurt their stomach linings. Please help.

What are strategies for drinking less in a social situation or for avoiding driving while impaired?

Recently, many of my friends have been doing methamphetamines. Often when they start to come down, want to come down, want to "level" out their high, etc. they take Xanax!!! Now I know Xanax is an anti-anxiety drug, and meth speeds your heart up. So can mixing the two ("reds" with "blues") be especially bad? I keep trying to tell them that it doesn't sound like a good idea...but they know that I hate pills so they DON'T listen. "They know better!" But I haven't been able to find any info specific to my question in other places. CAN YOU HELP?

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?