Full disclosure for surgery.

Don't ask, don't tell doesn't cut it when your health is at stake. Be sure to tell your doctor everything when it comes to medicines you're taking and food supplements and herbals you use, especially if you're considering surgery.

It may be very risky business to withhold information, and the risks you take can be significant according to a new report from the University of Chicago. The authors conducted a review of the research literature of eight commonly used herbal supplements--echinacea, ephedra (ma huang), garlic, ginkgo, ginseng, kava-kava, St. John's wort, and valerian--looking for pharmacological effects relating to surgery and anesthesia.

They found that the effects were potent, in some cases seriously so, increasing the risk of bleeding during surgery (garlic, ginkgo, and ginseng), cardiovascular instability (ephedra), hypoglycemia (ginseng), or increasing the effects of anesthesia (valerian] and kavakava). But don't take it upon yourself to stop abruptly since there may be withdrawal effects with some supplements. Talk with your surgeon to develop a safe plan.

(Journal of the American Medical Association, 2001, Vol. 286, No. 2, pp. 208-216)