They can't say, for example, why previously healthy people will suddenly find themselves with asthma. Nor can the experts figure out why some communities suffer far more than others. York's biggest asthma hot spots. We really don't know. There are plenty of theories about the dramatic upsurge, but none are definitive and some are contradictory.
Most doctors call the disease multi-factorial academic jargon to describe numerous causes.
This theory holds that vaccines and antibiotics have prompted immune system to react to the smallest irritants, such as dust or animal dander. Overall pollution is down, but areas with high concentrations of airplane and truck exhaust report that asthma is up. Fewer people smoke, but the rate of young people picking up the habit, especially young women, has increased. A Boston study found that kids exposed to the sound of gunshots or violent incidents were twice as likely to experience wheezing or use a bronchodilator, or be diagnosed with asthma after age 2. A major study by the National Institutes of Health last year named cockroaches and their residue as a prime culprit.