According to the Asthma and Allergy Foundation of America, adult onset asthma affects approximately 15 million people in the United States. In older adults, asthma symptoms sometimes mimic other illnesses, and the natural decrease in lung function that comes with age may make it more difficult to diagnosis. Unlike children with intermittent symptoms, adults newly diagnosed with asthma are more likely to experience persistent symptoms and require daily medication.
Exercise
Shortness of breath and wheezing during or after exercise may be more than a sign of being out of shape, says MayoClinic.com. Aerobic exercise, or any workout that causes heavy breathing, can trigger asthma symptoms. Environmental conditions such as air pollution or inhalation of extremely hot or cold air, should also be considered. Medical treatment should be sought if recovery is not complete within 15 to 20 minutes, or if symptoms worsen.
Obesity
Research suggests a strong association between obesity and asthma. In a study conducted by Palo Alto Medical Research Institute in California, and reported in the medical journal "Allergy," researchers found obese people were three times more likely to develop asthma than those of average weight. Although a direct relationship is not established, some suggest the systemic inflammation that frequently accompanies excess body weight, may contribute to development of allergies.
Viruses and Infections
Symptoms of adult onset asthma often appear following a bad cold or other viral infection. Difficulty in breathing, wheezing, tightness in the chest and breathlessness following an upper respiratory infection can be particularly severe and require hospitalization. Asthma symptoms may worsen when people self-medicate with aspirin or other non-steroidal anti-inflammatory drugs. Approximately 10 percent of adults develop aspirin induced asthma, says the University of Maryland Medical Center.
Allergens
Allergies cause at least 30 percent of adult onset asthma, says the Asthma and Allergy Foundation of America. Irritants such as pet dander, dust, mold, chemicals and perfume--often tolerated earlier in life--are common triggers for adult onset asthma. Although secondhand smoke can contribute to asthma symptoms, adult onset asthma is not caused by smoking, according to the National Institutes of Health.
