When you're in pain, the prospect of having someone stick needles into your body may not seem like the greatest of ideas. Yet most of the more than five million Americans who visit acupuncturists each year are doing just that.

Increasingly, research experience is showing Western practitioners that when it comes to certain conditions, acupuncture can be just as effective as conventional treatments like medications.

"It's not so much that acupuncture is used in every instance to eliminate drugs. It may be used to reduce reliance on drug therapy as a way to deal with symptoms," says James Dowden, executive administrator at the American Academy of Medical Acupuncture, a professional society of physicians who are trained to practice acupuncture and seek to incorporate it into their practice. "It becomes an alternative way to address a chronic condition."

Acupuncture has been used for thousands of years by Chinese practitioners for a wide array of ailments, but it is only recently that it has moved from the fringe of Western medicine.

A critical moment came in 1975, when New York Times reporter James Reston wrote about his experiences with acupuncture to relieve pain following an appendectomy in China. "That really started to open the gates for the first time to the West considering acupuncture as anything other than something bizarre and off the beaten path," says Dr. James Dillard, assistant clinical professor, Columbia University College of Physicians and Surgeons in New York.

The first license was granted to an acupuncturist in the United States the next year. Yet until 1995, the Food and Drug Administration officially considered acupuncture needles to be experimental medical instruments.

Further strides were made in moving acupuncture towards the center of heath care in 1997, when the National Institutes of Health released a consensus statement on acupuncture in which a 20-member panel endorsed its use for pain and nausea and suggested it may be helpful in other conditions.

" Interactive: Acupuncture For What Ails You?

"Since that time, and certainly with the increasing interest in alternative and complementary medicine, there has been an increase in published literature on acupuncture," says Dillard. "Instead of tens of papers, we now have hundreds of papers in the literature and more in the pipeline."

It's Ancient History

As scientists continue their quest to understand the potential uses of acupuncture and how it relates to Western medicine, they are also striving to understand more about acupuncture's great mystery ��?to figure out precisely how the simple insertion of a handful of tiny needles under the skin can bring about physiological changes in the body.

The ancient Chinese belief about acupuncture is that humans have energy or "qi" (pronounced "chee") running through channels in our bodies called meridians and ill health is related to a blockage in the flow of this energy.

"The idea is that you put a needle on a point along the meridian and hopefully stimulate the points to reopen the channels," explains Lixing Lao, a licensed acupuncturist and associate professor in the Complementary Medicine Program at the University of Maryland in Baltimore.

"The meridians are not only distributed on the surface, but they also connect to the internal organs," he adds. "So that's why stimulating the points on the surface can stimulate the organs inside."

There are more than 2000 of these acupuncture points distributed on the body. Stimulation of the right sequence of these points is thought to be effective in addressing certain problems.

The Connective Tissue Connection

So how do scientists think that these hair-thin needles can make you feel better? One of the most widely accepted theories of acupuncture is that the needles stimulate endorphins ��?the feel good chemicals associated with the "runners high."

"When you perform the acupuncture treatment, there is a release of endorphins that have the effect of increasing the sense of well-being and making the patient feel better," explains Dowden.

This theory may explain why acupuncture relieves pain and stress and why some studies suggest it may help depression. Other theories speculate that acupuncture may increase one's threshold of pain, thereby making people better able to tolerate it later on.

Other researchers have focused on what happens when needle meets tissue in the hands of an experienced practitioner.

"When the needle is inserted into the tissue in acupuncture, the acupuncturist manipulates the needle for a certain amount of time to achieve a certain reaction called de qi [day chee]," says Dr. Helene Langevin, a licensed acupuncturist and research assistant professor in the department of neurology at the University of Vermont in Burlington. This sensation is compared in ancient Chinese texts to a fish tugging on a fishing line.

"We found in animal studies that connective tissue tends to wind around the needle when it is rotated," adds Langevin. "All it takes is a small amount of winding and after that any movement of the needle will pull on connective tissue."

This pull on connective tissue may be sending mechanical signals to the surrounding cells, including cells of the nervous system, which may further explain its mechanism of action. The next step, according to Langevin, will be to find out what is happening on a cellular and molecular level.

Moving Into Mainstream

One of the reasons that acupuncture has been so well-embraced in the West may have to do with its low rate of side effects.

"For a medical procedure, you almost cannot get anything that is more benign," says Dowden. "About the worst thing that can happen is you won't get better."

Side effects include minor bleeding, bruising, and lightheadedness. Extremely rare is the possibility of a collapsed lung, which experts say is highly uncommon and only likely to happen with careless practitioners.

"In hospitals, we put a regular venipuncture needle right into somebody's artery and take a blood specimen and put our finger over it for a minute to stop the bleeding," reasons Dr. Woodson Merrell, a physician acupuncturist and director for the Center for Health and Healing at Beth Israel Medical Center in New York City. "Compare this to an acupuncture needle, where you can fit half a dozen of them over the whole of the needle used to [take blood]. Because of that the risk of side effects is very uncommon."

However, because these risks are even lower for experienced acupuncturists, Merrell offers tips on how to find a well-credentialed practitioner.

"Even if somebody has a license, that doesn't mean that they're good," he cautions. " [But] being a member of a state association shows that they're actively involved in getting continuing education credits, and someone who has been in practice for a number of years and have some experience under their belt."

Additionally some states have online sites where you can check to see if there are any actions being taken against practitioners. And don't discount good old-fashioned word of mouth as more and more people seek out acupuncturists as an effective, low-risk way to approach their health problems.

"Ten years ago, it was probably considered in the quackery area by the more conservative physicians," says Merrell. "Now it's being considered as a practice that people can think of for patients the same way that they can think of giving a drug or physical therapy or surgery. Eventually it will just be part of mainstream care."

From ABCNews.go.com