It’s not your imagination; the weather can cloud your health. Here’s what research reveals about the connection between weather and arthritis pain.

Changes in temperature or barometric pressure, a measure that refers to the weight of the surrounding air, trigger joint pain, though researchers aren’t entirely sure why. In 2007, researchers at Tufts University in Boston reported that every 10-degree drop in temperature corresponded with an incremental increase in arthritis pain. Increasing barometric pressure was also a pain trigger in the Tufts study.

In fact, studies in cadavers have found that barometric pressure affects pressure inside the joints. In one experiment, when pressure in the hip joints was equated with atmospheric pressure, it threw the ball of the hip joint about one-third of an inch off track.

Asthma Also Can Be Affected

The conventional wisdom that thunderstorms wash pollen, smoke, mold and pollutants out of the air, making it easier to breathe, may be wrong, according to scientists at the University of Georgia in Athens and Emory University in Atlanta. Climatologists and epidemiologists who looked at 12 years of records from 41 hospitals around Atlanta, found that visits to the emergency room for asthma spiked on the day after a thunderstorm. The link got stronger during storms with moderate-to-high wind gusts and moisture.

Though they aren’t sure why asthma gets worse after a storm, the scientists think that rain causes pollen grains to burst into pieces that are even smaller and easier to inhale. Lightning in the atmosphere may also spark a chemical reaction, turning pollutants into asthma triggers.

Weather Can Activate Migraines

Studies have found that 50 to 80 percent of all people who get migraines believe weather can set off a headache. The exact weather patterns that precipitate migraines remain a mystery, however.

In a study published in 2004, Patricia Prince, MD, of Boston Children’s Hospital, asked 77 migraine sufferers to keep calendars documenting their migraines over a period of two years. She then compared those to records kept by the National Weather Service.

About half of study participants got migraines that coincided with weather changes, but not all who were weather sensitive had the same triggers. Some seemed most vulnerable to a combination of high heat and high humidity, while others got headaches under the exact opposite conditions – low temperatures and low humidity.