Since my 15-year-old son was born, he has been a great milk drinker. Now, at 6ft tall, healthy, active and without an ounce of fat on him, he drinks between 12 and 16 pints of milk a week, and we're a little worried about the possible long-term effects. He is of mixed Indian/English background – I say this because I know that lactose intolerance can be a problem for Asians, having experienced it first hand. What can we advise him?
Your son certainly isn't lactose intolerant. If he is healthy and of normal body shape, I don't see that you have anything to worry about. If you are concerned about his risk of heart disease, he could talk to his doctor, but don't worry: milk has had a bad press over the years, but it seems to be sustaining your son in a healthy state. There are a whole lot worse teenage habits to have than drinking a lot of milk.

I sweat excessively, particularly around my forehead, armpits and hands. I also overheat to the point at which I feel as though I have a temperature. My GP wasn't very helpful when I asked about this – can you suggest a remedy?
The most common cause of such excessive sweating is overactivity of the nerves in the autonomic nervous system which control a host of glandular secretions – technically, the cholinergic nerves. So a prescription for an anticholinergic drug may help. The snag is that such a drug would also affect other areas of autonomic nerve control, such as tear and saliva production, eye muscles, digestive system, heart rate, bladder and bowel function. So if you can put up with dry eyes and mouth, constipation and difficulty in passing urine, and maybe even palpitations, you could try one of the drugs on the market. This may explain your doctor's reaction – he or she is probably reluctant to prescribe such drugs. However, if the sweating is so bad that it is affecting your quality of life, and medication doesn't help, surgery to sever the appropriate nerves might be considered. Talk to your doctor again: I'm sure he or she will be sympathetic – presumably they've ruled out other causes, such as a chronic infection.

• Got a question for Dr Tom? Email doctordoctor@theguardian.com