However, in addition to the sites that focus on particular illnesses and ailments - like asthma, for example - there are numerous general health sites covering a broad range of health topics. Many act as online encyclopedias, marshalling information on symptoms and cures to give overviews of different topics.
Other sites have sprung up to sell medicines and pharmacy goods, and we take a look at a couple of these e-dispensers.
A large number of sites is one thing, but can you trust them with your health? Is there a danger in turning to the Web rather than visiting your doctor? Nearly all health sites included in this story warn visitors that the service should not be viewed as a replacement to visiting your doctor. If you have a niggling health concern, however, these sites could point you in the right direction for treatment and help, and give you an overview of what to expect when you do visit your doctor.
The other thing to keep in mind is impartiality. Does the site's advice conveniently recommend sponsors' products? Who, or what company, is behind the site? Take the time to first do some research on the site to understand whether it's a valuable tool. For more tips for using health sites, see the box "Tips for healthy living online".
GENERAL HEALTH SITES
DIET AND WEIGHT LOSS SITES
There are loads of sites catering to people who are looking to lose a few kilos - from real-lift stalwarts like Jenny Craig and Weight Watchers to online-only options. Here's a sample:
The world of the chemist has not been immune to e-commerce. You can now order your prescriptions online, although you will need to mail the paper version (no faxes) for verification.