Question: What is the relationship between asthma and allergy?
Answer: People with allergies are definitely more susceptible to asthma. And let's start by talking a little bit about allergies, which is a pretty complex topic. Allergies are immune system reactions to substances -- for instance, dust mites or cat dander -- that lead to the release of chemicals in the blood that cause the symptoms that we associate with allergies, such as an itchy, runny nose at one extreme, but at the other, anaphylactic shock, and even death.
So there's lots of evidence that people who have allergies are more likely to develop asthma. And that's usually the sequence of events with early signs of allergy than asthma. However, there are people with asthma who don't have any allergies, and it's an important subset that we need to remember.