• Viral infections
• Allergies, such as ragweed and pollen, aspirin, animal dander, or dust
• Chemical exposures, such as cleaning with bleach in a non-ventilated area
• Acid reflux (heartburn can spill chemicals from the gastrointestinal tract into airway)
• Smoking
• Cold air, during winter or from air conditioning
• Exercise
• Stress
• Obesity

Asthma is known to have a number of different presentations. People at risk for asthma often have a family history of asthma, but it can occur in patients without any family history of the disease. Although it was previously thought that the onset of asthma only occurred in childhood, we now know that there are patients for whom asthma starts even later in life. In fact, patients with asthma that starts in adulthood tend to have more severe disease that does not respond to treatment as well. Asthma is more common in those who have a history of allergies (seasonal) or atopy (immediate allergic reactions).

When asthma starts in childhood it may resolve in the late teens and early 20s. Patients will report that they have “grown out" of their asthma. However, in some cases, there is a period of minimal asthma symptoms as a young adult but a recurrence of asthma later in life.  Therefore, patients that “grow out of their asthma” must recognize the possibility of a recurrence and pay attention to any asthma symptoms that return later in life and should seek treatment if this occurs. While boys are more likely to have asthma during childhood, more females have asthma as adults.

There are several different types of asthma with varying causes and degrees of severity. The different types of asthma are described as phenotypes, which are the characteristics of a disease that can be observed (and measured using certain tests). These phenotypes are produced by the interaction of a person's genetic predisposition and the environmental triggers that cause the disease to occur. The asthma phenotypes include:  

Regardless of the type or severity of asthma you have, your physician should focus on controlling it. You cannot control the type or severity of asthma you have, but you can focus on achieving control of your disease.

Uncontrolled asthma is defined as:

• Poor symptom control OR
• More than two exacerbations/year (attacks of asthma that require treatment with oral steroids like prednisone or require you to go to urgent care/ER or hospital for your asthma) OR
• At least one hospitalization or ICU stay per year OR
• Low lung function (<80% FEV1 – the amount of air that you can blow out of your lungs in one second)

Achieving asthma control is the central focus in the management of patients with asthma. Other goals should include preventing progression of your asthma and limiting exposure to medications beyond what is required. Finally, your personal goal should be to live a productive and symptom-free life with asthma.

View more Asthma resources in the U-M Health Patient Education Library