In this entry, I would like to address the issue of what happens to asthma as we get older, and specifically how this is affected by how bad our asthma is at different times on our lives.
Asthma and age
For most patients with asthma, symptoms of shortness of breath, wheeze, and cough are episodic, in many cases related to exposures in the environment that are "triggers." These can range from strong odors to allergens (e.g. pet dander, pollens) to the common cold.
Most asthmatics have a pretty good sense of what their triggers are. Over time, we notice periods of weeks or months that our asthma is under better or worse control -- which can be related to these exposures, stress, and how regularly we are taking our medications.
It is more common for asthmatics, especially children, to experience an improvement in asthma symptoms as they get older. While scientists are not sure why this happens (since our environment doesn't change that much), it is probably related to the fact that many children and young adults "outgrow" their sensitivity to allergens in their environment. (Have a look at an earlier entry on the close relationship between asthma and allergies for more detail on this connection.)
While many young asthmatics outgrow their asthma, about 20 percent of asthmatics develop asthma in adulthood. But once again, control is most often determined by environment and other factors more than simply getting older.
Specific measures of lung function with age and asthma
While asthma symptoms and control on the whole do not have a predictable decline with age, there are scientific studies that have looked at precise markers of lung function ('pulmonary function tests') over time. As background, markers of lung function measured by pulmonary function tests have shown a gradual decline in normal, healthy individuals starting around age 25. When these markers are assessed in asthmatics, as a group this decline in lung function occurs at a slightly increased rate. A very important finding in these studies was that this decline was significantly faster in patients with asthma who also smoked cigarettes.
In addition, the situation may be a little different in patients with severe asthma of long duration, who need to be in the hospital for their asthma and at times require multiple medications to control their symptoms. Their lungs suffer longstanding and repeated inflammation from asthma, and some studies have shown that their airways (bronchi) undergo "remodeling." This remodeling causes the walls of the bronchi to be stiffer, not respond as well to asthma medication, and may also cause worsening symptoms with age.
Whether asthma symptoms or lung function get worse with age are unanswered questions, but it is clear that there is little we can do to "stop the clock." On the other hand, asthmatics can participate actively in controlling their asthma by talking with their doctors about tips to avoid triggers, taking medications regularly as prescribed, and most importantly, not smoking cigarettes, which seem to have a particularly bad interaction with asthma in terms of looking forward to how we breathe.