This one seems obvious, but sometimes people are scared or otherwise reluctant to just ask their doctor. Your doctor should be willing to explain your condition to you and she may have pamphlets or other materials on your condition that can help you to begin understanding your condition.
Do On-Line Research
Some on-line research can be very helpful, particularly at sites that are sponsored by nationally recognized organizations associated with your illness, e.g., the American Heart Association or the American Cancer Society.
Review Reference Materials
You may want to buy reference materials like a medical dictionary. If you are concerned about your medications, consider reviewing the most current Physician's Desk Reference, which can supply you with information about your medication, including side effect information.
Get a Second Opinion
Consider whether there are any medical centers near you that specialize in your condition. A second opinion is always a good idea even if you don't go to a specialty center.
Trust Your Judgment
Most importantly, never stop thinking, evaluating and asking. You are your best protection against an avoidable medical error. If you blindly trust your healthcare providers, you are essentially giving up the best protection you have.