Several popular herbs lengthen the time it takes for blood to clot. This is accomplished by hindering the ability of the platelets to clump together. In many situations, this is a good thing.

Blood clots that form in the brain can cause a stroke. If blood clots form in the arteries of the heart (cardiac arteries), it can cause a heart attack.

Herbs with clot-preventive benefits include garlic (Allium sativum), ginkgo (Ginkgo biloba), ginger (Zingiber officinale), and feverfew (Tanacetum parthenium).

So if you take so-called anticoagulant (anticlotting) drugs, whether it's over-the-counter aspirin or the potent prescription drug Coumadin (warfarin), use these herbs only after checking with your doctor.

Before your scheduled surgery, your surgeon will usually tell you to stop taking anticoagulant drugs a few days before the procedure. But I am sure he/she will not ask you what food supplements and/or herbs you are regularly taking. And less likely that your doctor will ask about anticoagulant herbs you may be taking. So be sure to ask whether you should stop taking herbs such as garlic, ginkgo, ginger, or feverfew before surgery. As a matter of fact, it's always a good practice to discuss everything you take— drugs, herbs, or other dietary supplements—with your doctor.

Write this suggestion down in your pocket notebook with the other questions you have for the doctor so you will not forget to bring it up when you get those few moments with the surgeon.