If your achy knee "tells" you when it's going to rain, you already know weather can have an impact on your body. Here's an expert look at how what's happening outside can affect how you feel inside — and it's not always negative:
Lightning: Increased Headache Risk Lightning storms may trigger headaches and migraines in chronic sufferers, according to a study by University of Cincinnati researchers recently published in the journal Cephalalgia. The study detected a 31 percent increase in the risk of headaches and a 28 percent increase in the risk of migraines among chronic sufferers on days when lighting struck within 25 miles of participants' homes. Others were affected as well: researchers found a 24 percent rise in new-onset headaches among study participants.
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The study accounted for other weather factors, suggesting that lightning has an independent effect on headache risk. The exact reason is not clear, but the study's lead researchers think electromagnetic waves emitted from lightning may be the trigger. Lightning also increases the volume of ozone in the air, and can release fungal spores that can bring on migraines. (You can't control the weather, but you can trim your risk of migraines by avoiding trigger foods such as chocolate, red wine and processed meats and cheeses.)
Smog: Respiratory Threat If you live in a city or region with a good deal of air pollution, you may face a higher risk of cardiovascular and respiratory problems. Johns Hopkins University researchers have linked exposure to fine particle matter in the air — in other words, smog — to an increased risk of hospital admissions.
"Smog affects the cardiovascular system in many ways," says cardiologist Stephen Sinatra, author of The Great Cholesterol Myth. "When you inhale particles, smog puts stress on the lungs, which could thereby increase pressure in the heart causing a rise in pulmonary artery pressures."
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Air pollution can also increase the activity of the autonomic nervous system, which controls the body's vital, involuntary functions, including heartbeat. "Breathing in clean air or filtered air is essential in protecting the cardiovascular system," Sinatra says.
Fog: Respiratory Relief Unlike smog, fog may actually benefit people with respiratory problems by cleaning the air. The most beneficial type of morning fog for this effect is known as "radiation fog," which forms when skies are clear and the atmosphere is stable. As the sun rises and evaporates water droplets, dirt and dust particles in the air fall to the ground.
Your nose, mouth, throat and upper airways are naturally efficient at filtering, says Dr. Raymond Casciari, chief medical officer of St. Joseph Hospital in Orange, Calif. But small particles can still reach the alveoli, the tiny air sacs in your lungs, and cause damage. By clearing those particles from the air, he says, "fog can be a beneficial situation."
Storms: Depression Link The sharp drops in barometric pressure that typically occur before a storm may increase the risk of depression symptoms in some individuals, especially those prone to seasonal affective disorder, according to research from a University of Barcelona team. In fact, their study suggests the condition may be more closely related to weather conditions than regular seasonal changes.
A separate study conducted by University of Louisville researchers and published in the Canadian Journal of Psychiatry linked low barometric pressure to an increase in emergency psychiatric visits, particularly those related to violent acts.
"When weather creates mood changes, the goal is to figure out how to improve the moment," says Lisa Bahar, a licensed professional clinical counselor in Orange County, Calif. She suggests using imagery to get through a storm-related crisis: Imagine a calming, beautiful environment, maybe with the help of meditation recordings. Or distract yourself by going to a movie, reading a book or listening to music. "The key," Bahar says, "is to find a distraction from the depressive feeling," sparking a shift to a more content state of mind.
Cold: Arthritis Aggravation People with rheumatoid arthritis often experience flare-ups of achy joints during cold weather, a symptom confirmed in a recent study by Spanish scientists. They found that patients between ages 50 and 65 who visited an emergency room due to rheumatoid arthritis-related complaints between 2004 and 2007 found that they were 16 percent more likely to experience flare-ups in cold temperatures.
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One theory links the drop in air pressure that often accompanies cold, rainy weather to increased inflammation and pain as tissues in the body expand. "While some of the data is mixed, my patients certainly complain more during damp, cold weather than when it's sunny and warm," says rheumatologist Nathan Wei, director of the Arthritis Treatment Center in Frederick, Md. Exercising in an indoor gym or heated pool may help ease the symptoms, he suggests.