Ask an Expert: What Are the Risk Factors for Asthma?

Asthma is a condition that causes airways to narrow and swell, often making it difficult to breathe and leading to coughing and wheezing.

Asthma often starts at a young age and can be triggered by viral respiratory infections, allergies, obesity, and other factors. Genetics also plays a big role—people who have a parent with asthma are 3 to 6 times more likely to develop asthma.

Where you live and work can make a difference, too. Occupational exposure to certain dusts and chemicals in the workplace can cause adults to develop asthma later in life. Air pollution in urban spaces and smoking—or exposure to secondhand smoke—can irritate the lungs and trigger symptoms.

Your environment, behaviors, and access to health care make a big difference in how likely you are to develop asthma and receive appropriate treatment for it. Unfortunately, due to disparities in society and the health system, this means some groups are disproportionately affected by asthma.

Farah Khan, M.D., an allergist and immunologist, explains the risk factors for asthma and where the health system falls short.

What are the main risk factors for asthma?

Dr. Khan: The biggest risk factor is probably your genetic predisposition. If either of your parents, especially your mom, has any allergic predisposition or asthma herself, it puts you at a slightly higher risk.

If young infants develop eczema or food allergies, that also puts them at a higher risk of developing asthma later on. There are also kids who don’t have eczema and food allergies, but they go on to develop pretty bad environmental allergies which also put them at risk.

Wheezing during colds and upper respiratory infections is often expected, and if you’re only wheezing in those episodes, you’re more likely to outgrow [asthma] by the time you’re of young elementary age. But if you start wheezing apart from those colds, that is more concerning and a risk factor for developing more persistent asthma.

Some of the smaller factors that are still pretty important are things like pollution levels and smoke exposure. Teenagers are engaging in risky behavior with either smoking or vaping and, unfortunately, we’ve seen that have terrible consequences. When parents smoke at home, even if they swear they smoke outside, all of the particles from the smoke exposure track through the house and expose the kids.

Tell us more about those environmental risk factors, especially in terms of where a person lives and the kind of work they do.

Dr. Khan: Occupational asthma is definitely a very real thing. We see it in patients who are exposed to compounds that sensitize them and can cause them to develop allergic asthma. Sometimes we see this in bakers because flour can do it. We see it in folks who are dealing with different enzymes or rubber-derived proteins. We can see it in workers who are handling seafood, and those exposed to metals and chemical substances. We typically see occupational asthma in adults, and [it's] its own sort of category.

We do see higher levels of pollution in more congested cities. And with climate change, we’ve been seeing seasonal changes occurring sooner and lasting longer than we normally would. Unfortunately, there are folks that still smoke, especially in urban environments, where we see more crowded housing and poor ventilation or increased roach exposure and dust mite sensitivities, it also impacts asthma control.

Another risk factor is obesity. We know that the more weight you’re carrying, the more your lungs have to work. Among all of the other childhood obesity issues that we’re dealing with, we also worry about these kids going on to develop more significant asthma.

What are the disparities in terms of who is at higher risk for developing asthma?

Dr. Khan: We do see more instances of severe uncontrolled asthma in lower socioeconomic status urban settings. It’s multifactorial—sometimes it’s whatever genes they’ve inherited from their parents, but then also their environment.

For instance, if they are living in crowded housing, if they don’t have access to a primary healthcare provider, if they’re non adherent to medications [taking their medication] because they can’t afford it, they don’t have a ride to the pharmacy, or if they’re not on the right medication, they may end up getting really sick and presenting to the emergency room. When we get them better, they go back into the same environment and fall into the same habits.

Even if we can work through some of the health-education barriers and patients understand the impact, sometimes financial circumstances get in the way. Some patients or parents will work two or three jobs, and it’s very hard to take off from work and bring [their children] in for their quarterly appointment to check on their asthma.

Those were probably the biggest takeaways from my experience working in an urban setting. Over the last couple of years, I’ve been working in a private practice setting. A lot of my patients choose to come see me, so I don’t really have issues with adherence and compliance and access to medication or health care.

What are some of the systemic changes that must be made to reduce disparities in asthma risk?

Dr. Khan: This is a really hard question because I think every healthcare provider who works with patients from a lower socioeconomic status wants to do what’s right for the patient. We want to empower them to understand why smoking or not taking their inhaler every day is putting them at risk. But the system really isn’t set up to promote that message, so it comes down to individual providers.

I’m not very optimistic right now about where healthcare delivery is. I think the pandemic highlighted a ton of dysfunction. I worry about the families who don’t come in for regular wellness checks, let alone the routine asthma follow-ups.

Is there any way for people to avoid an asthma diagnosis or reduce the severity of their asthma?

Dr. Khan: You can’t really do anything about the genes that you’ve inherited. If your mom or dad has asthma, you’ve got some genetics that are working against you. But there’s definitely an environmental punch in terms of when patients start manifesting symptoms.

If you have a genetic predisposition for allergy and you’re also in daycare as an infant or toddler, you’re going to be exposed to more viruses, which can lead to more illnesses, which could lead to more wheezing episodes, potentially catapulting you into a full-blown asthma diagnosis.

It’s important even in my young patients that have asthma, like the 6- and 7-year-olds and young teenagers, to empower them to be compliant with their medication and identify any potential gaps in getting their inhalers and medications. That may mean connecting with a social worker, putting the asthma diagnosis on the existing social worker’s radar, or checking in with parents about what kind of support they need.

It can often feel like we are trying to play catch-up with the system rather than the system serving our patients, which is really frustrating and sad. But when we can, we really like to optimize somebody’s adherence to their inhaled steroid therapy or other medicine so that they don’t end up in the emergency room and rack up a $5,000 hospital visit stay because they were out of meds that could have cost them $100 or $200 over the course of the previous few months.