Dear doctor

Q My 16-year-old son has been advised by his orthodontist that he needs to have some teeth removed to ensure straight teeth. He is point blank refusing. Can we force him to have it done?

A Legally (Family Law Reform Act 1969 for the lawyers among you - and please don't sue me if I'm wrong), he is considered capable of consenting to treatment but not able to refuse. This means that if he said yes, the treatment could go ahead whether you wanted it or not. But if he says no, the orthodontist can explain to you why he thinks the treatment is in your son's best interests, and you can override your son's decision. If your son needed a life-saving operation, such as removing his appendix, it would obviously be worth forcing the issue. In a cosmetic matter like straight teeth, you may want to explore with him why you think it's a good idea and what he's so worried about. But if he still digs his heels in, perhaps it's best to drop it.

Q I have to travel to San Francisco for work. I'm concerned about economy class syndrome and developing thrombosis. Should I fork out for business class?

A It depends who's paying! If it's you, don't bother on health grounds. Thrombosis transcends that discreet curtain that marks the class barrier on planes. "We" have less leg room but "they" get more alcohol, which also increases the risk. They also share the same dry, low-pressure air. Flying more than 10,000km/s as you are about to, results in 4.8 cases of thrombosis per million passengers, of which few are dangerous. To minimise your risk, avoid alcohol, drink one litre of water every six hours, walk around when you can, and wear below knee stockings. Experts quibble about aspirin, but if you're not allergic, asthmatic or dyspeptic - why not? With aspirin, less is more, with 75mgs working very nicely while hefty doses over 300mgs actually increase your clotting tendency.

Q I've been getting a nasty metallic taste in my mouth. Could it be a medical condition?

A Far more likely to be iatrogenic - ie caused by doctors - or dental. A metallic or unpleasant taste in your mouth is a fairly common side effect of a number of drugs, such as the sleeping pill Zimovane A. Furred tongue and an unpleasant taste in the mouth can occur with the antibiotic Flagyl, and the anti-fungal drug Lamisil can impair your sense of taste. It's worth seeing your dentist to discuss likely oral causes.

Q I'm a 30-year-old man with a rapidly receding hairline. Do you advise the new anti-baldness pill?

A The drug finasteride has been around as a prostate-shrinking drug for about a decade. Now a lower dose version has been repackaged as an answer to male pattern baldness, under the name Propecia. It costs about £30 a month and is available on private prescription from a GP. It blocks formation of the active form of the male hormone testosterone. In a test, 1,553 men aged 18-41 with hair loss took either 1mg of finasteride a day for a year or a placebo. The placebo group lost an average 2.7%of their hair, the finasteride group increased theirs by 11%. Side effects were few but included temporary loss of libido and impotence. If you stay on the treatment, both your erections and hair come back, with a bit of luck. Once you stop the treatment, the hair loss starts again.

Q I'm 80 years old, five foot nine inches, and weigh just over 10 stone. I've always had a small appetite and been a slow eater. I have been finding it increasingly difficult to swallow and wonder whether it could be due to too little saliva. Can you help?

A It may well turn out to be a harmless matter of too much stomach acid or too little saliva. But you really need to get this investigated urgently. Within two weeks, your GP should be able to get you seen by a gastroenterologist who will probably look directly into your stomach while you are lightly sedated. He will be looking for narrowings which may be caused by a malignant or benign growth. Most narrowings can be treated to make your swallowing easier.

· These answers are intended to be as accurate and full as possible, but should never be used as a substitute for visiting a doctor and seeking medical help. If you have a question for Dr Robinson, email drann@dircon.co.uk or write to her c/o The Health Editor, The Guardian, 119 Farringdon Road, London EC1R 3ER. She regrets that she cannot enter into personal correspondence.

Thanks to guardian.co.uk who have provided this article. View the original here.