Dr Tom Smith on the best types of sleep, cures for tinnitus, and chronic constipation

I am exhausted at the moment by a late-night schedule of work and study. I've heard that the hours of sleep before midnight are more regenerating than those after. If so, should I alter my sleeping hours to increase my brain power?

The crucial advice for you is that when you start to feel tired in the evening, say after 10 o'clock or so, you should give in to the feeling and go to sleep. Fighting that and keeping on working is a mistake on several fronts: the study or work you do when you are tired will not be as effective or productive as that you do when you are wide awake; when you do turn in, you will find it more difficult to get to sleep; and the quality of sleep after working too late will not be refreshing enough for you to concentrate in the morning. In effect you will have a non-alcoholic hangover. So listen to the message of your brain at night, and go to sleep when it wants to. Then you can wake up early in the morning if you need to, to study or work.

My elderly aunt has recently developed tinnitus. She fears that it may lead to permanent loss of hearing. Is there any cure?

How well tinnitus can be treated largely depends on its cause. This can vary from wax in the ear (I presume that has been ruled out) to noise from a hardened carotid artery (which runs near the ear) or Ménière's disease, which is caused by raised pressure inside the inner ear. If it is the last of these, then specific prescription drugs, such as betahistine or cinnarizine, may help. So the short answer is that a lot can be done: she needs to seek help either from her doctor or an ENT consultant.

Since the age of 18, I have been chronically constipated. My grandmother died of colon cancer. Could this be a precursor of the same? I eat healthily and take lots of exercise, but should I worry?

Almost certainly not. Chronic constipation without any other symptoms is not linked to an excess risk of colon cancer. Are you sure you are getting enough fibre and roughage in your food, as well as plenty of fluids? That should help. The one small doubt, however, is your grandmother. Colon cancer does tend to be inherited, so it wouldn't do any harm to ask to be referred to your local bowel department. A colonoscopy, if that's what the experts think you need, would ease your fears.

• Do you have a question for Dr Smith? Email doctordoctor@guardian.co.uk

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