If you seem to have an endless cold, you may actually have an insect allergy. Cockroaches in particular are everywhere but are especially common in warmer climates and in crowded cities. They thrive in humid rooms (think bathrooms and kitchens), are more active at night, so they will scatter when a light is turned on.

Cockroaches have a protein in their body parts, saliva, and waste that can set off allergy symptoms and asthma, even after they are dead. Your symptoms may be worse during or after cleaning your home because vacuuming, sweeping, and dusting can kick the reaction-causing protein up into the air, making it easier to inhale.