Do your creaky old knees predict the coming storms better than the local weatherman? Does your asthma flare up when the temperature drops? And are you more cheerful when the sun is shining? If so, you're simply experiencing typical health fluctuations that occur with changes in the weather.

An old wives' tale, you're thinking?

Probably not. William Seeds, M.D., an orthopedic surgeon in Ashtabula, Ohio, knows that when the barometric pressure falls rapidly -- as it does frequently in the Lake Erie area, where he practices -- that he's going to be hearing from his arthritis patients.

"My patients can definitely correlate the changes in [barometric] pressure with their pain," says Dr. Seeds. "They can actually predict the weather by feeling how their joints are doing." Though Dr. Seeds has found no current clinical trials that scientifically confirm the relationship between barometric pressure and joint pain, his patients' consistent complaints have made him a believer. As a result, he now suggests that arthritis sufferers go on the offensive when it comes to tackling their weather-related pain.

"Be prepared," Dr. Seeds advises. "Rearrange your activities if necessary, and pre-medicate with an over-the-counter anti-inflammatory or with your prescription pain medication. This approach has proven very therapeutic."

Predictions from the meterologists

The cause and effect between weather and health goes well beyond achy joints, says Joe D'Aleo, chief meteorologist for Intellicast.com. This popular website offers information on how weather may affect a number of medical conditions, such as aches and pains, respiratory problems, slowed reflexes, allergies, mental alertness, labor and birth, influenza, and moods.

"How you feel, how you perform, how you behave ... Weather affects all these things on an everyday basis," says D'Aleo.

The connection between weather and health is not new, he notes. As far back as 400 B.C., Hippocrates first wrote about the effect of hot and cold winds on people's health, as well as the possible link between epidemics and weather. Today, it's common knowledge that when the pollen count is high, your allergies are bound to flare up; that when days are shorter, the risk of seasonal affective disorder is higher; and that extreme heat can cause heat exhaustion, heat stroke, and even death.

New research, new fields of medicine

As awareness of the link between weather and health has grown through the years, it has given rise to the creation of a new field known as biometeorology, defined as the scientific study of the effect of weather on human health. Some of the resulting medical research supports existing anecdotal evidence.

A clinical trial conducted by researchers from Johns Hopkins University and the University of Pittsburgh, for example, found that cold weather might bring on heart attacks in men by constricting coronary arteries and decreasing coronary blood flow. Further research is needed to determine if there are ways to treat this cold-induced coronary constriction to prevent cold-weather heart attacks.

For everyday ailments, though, it may all come down to common-sense prevention. Whether it's making sure your child has her inhaler when she waits for the school bus on cold winter mornings, or taking pain medication when rain is on the way, knowing how weather can affect your health can help you avoid medical complications.