Keeping Windows Shut May Not Shut Out Allergies

Even if you close your windows at night to minimize the pollen that enters your home, there's still a chance you might suffer from allergy symptoms.

"Keeping your windows closed may not keep you pollen-free," says Richard Weber, MD, a physician at National Jewish Medical and Research Center in Denver. "You still could wake up stuffy with allergy symptoms. This is called ‘late-phase response.’"

Exposure to pollen and allergens during the day causes symptoms at the time, but it’s not unusual for symptoms to occur again 6 to 8 hours later. "Late-phase response is a reaction to an allergen from earlier that day," he says.

Grass, tree and flower pollen cycles differ throughout the year. It is important that allergy sufferers limit exposure during their specific allergy season, Dr. Weber suggests.