A comorbid medical disease, or comorbidity, is a condition that occurs in addition to the primary illness. For example, a person can have co-existing asthma (primary illness) and obesity (comorbidity).
Some comorbidities make asthma more difficult to control. Important asthma comorbidities include hay fever (allergic rhinitis), allergic bronchopulmonary aspergillosis, obesity, GERD (gastroesophageal reflux disease), obstructive sleep apnea, and anxiety and depression.
Since hay fever and asthma affect the upper and lower parts of the same airway, it is not surprising that they are closely linked. Having hay fever increases your risk of having asthma. For many people, treating hay fever improves asthma symptoms.2
Allergic bronchopulmonary aspergillosis
Allergic bronchopulmonary aspergillosis (ABPA) is an allergic reaction to Aspergillus fumigatus, a fungi found in soil.3 This fungi does not affect people with healthy immune systems. However, in people with asthma, it can damage to the lungs and airways.
Signs of a reaction to ABPA are high blood eosinophils, fever, and mucus with brown flecks.2 A chest x-ray or CT scan will show signs of damage. ABPA is treated with an oral corticosteroid and occasionally, with an antifungal medication. There is good evidence that treating ABPA can improve asthma control.2
Extra body weight changes the way the lungs function. It also alters the immune system and increases inflammation in the body.2,4Obese adults are more likely than lean adults to develop asthma.2,4 Children and adults who are obese are more likely to have persistent and severe asthma.2
Asthma medications do not work as well in people who are very overweight.4 Additionally, obesity increases the risk of other conditions, such as GERD and obstructive sleep apnea.
GERD is a digestive disorder and common comorbidity of asthma. Common symptoms of GERD are heartburn, regurgitation, chest pain, and dry cough.5 These symptoms happen when stomach contents such as food, fluid, and digestive juices back up into the esophagus (food pipe). GERD can lead to more asthma symptoms, especially at night. Treating GERD with medications can reduce nighttime asthma symptoms and asthma attacks.2
Obstructive sleep apnea
It can be difficult to tell obstructive sleep apnea apart from nighttime asthma. Both conditions have similar symptoms. In fact, they often overlap in the same patient.2 Sleep apnea can be a cause of poorly controlled asthma.2
Diagnosing sleep apnea requires a sleep study. Nasal CPAP (continuous positive airway pressure) is helpful for people with comorbid asthma and sleep apnea, but not for people with asthma alone.2
Anxiety and depression
Mental health problems do not cause asthma, but they do make asthma harder to control.2Anxiety and depression can get in the way of taking care of your asthma. This leads to more asthma symptoms and asthma attacks. People with mental health problems have more emergency department visits for asthma.5
Anxiety and asthma cause similar symptoms, such as shortness of breath and chest tightness. Furthermore, asthma symptoms cause more distress for people with mental health problems.6 It is not known whether treating anxiety and depression can improve asthma.6
What are other asthma comorbidities?
Have you experienced any other asthma comorbidities? Share your experience with us!