Asthma Basics: Seven Big Triggers

They may be cuddly, but cats are one of the top triggers for asthma. Dogs (and horses) can also cause symptoms.

Whether first-hand, second-hand or third-hand (smoke that lingers), cigarette smoke is a potent trigger.

Viral Infections, like the common cold, cause inflammation and wheezing, especially in children.

When sunlight strikes pollution from automobiles, factories and power plants, smog results, wreaking havoc on the lungs of asthmatics.

These microscopic cousins of the spider live in your mattress, sofa, carpet and stuffed animals. It is their droppings that make many asthmatics wheeze.

Ragweed is a mighty foe: one plant can produce a billion grains of pollen in a fall season. Pollen from trees (spring) and grass (summer) can also trigger asthma symptoms.

This fungus grows in damp, humid environments both indoors and outdoors. Its spores cause allergic asthma symptoms