They have increased from 50 million in 1998 to 175 million today, according to market research firm Harris Interactive. And they are also getting more active. 32% of all adults who look for health information 'often', is up from 22% last year.
A cyberchondriac is a person who looks for healthcare information online. The net is replete with medical information (and anything else you can possibly imagine). Just as with wikipedia, it is all not good information, but the masses of contributors level it out, so the good overcomes the bad.
People in record numbers use the web to look up information about a condition, treatment, a physician's credentials, or alternative forms of treatment, along with successes and failures of each.
PS - Some doctors do not like being questioned, so tread lightly with your new found information and questions. It is never a good idea to upset a waiter or a doctor.