What is asthma?
Asthma is a chronic condition affecting the lower respiratory tract (lungs). Cough, wheeze, a cough at night that keeps you awake and chest tightness are all symptoms of asthma and may present at any age, but are more common in young and middle-aged adults. Elderly persons can be breathless, but have little cough or wheeze.
Wheeze is a high-pitched whistling that occurs when air flows through narrowed airways. All people with asthma wheeze, at least occasionally, but it’s important to remember that not all people with asthma wheeze every time they are having symptoms. Indeed, in a very acute exacerbation (when asthma gets worse), a person with asthma may not be moving enough air to wheeze - this is called “silent chest” and is a life-threatening situation. Asthma symptoms vary over time and between persons, so one can’t expect to always see all symptoms in the same person at the same time.
The most important difference in timing of asthma symptoms is between symptoms that come and go (intermittent) and symptoms that persist. People with intermittent symptoms have asthma symptoms infrequently, few exacerbations (when asthma gets worse), and do not have symptoms in between. Everyone else has persistent symptoms: mild, moderate or severe. This classification system is used to determine severity and treatment and you may hear your health care provider talk about it.
Who gets asthma?
Childhood is by far the most common age of asthma onset and is usually associated with allergies too. Although childhood is the most common time of onset, people of any age may develop asthma. The triggering event for the development of asthma in an adult is often difficult or impossible to identify. A family history of allergy may or may not be present. Occupational exposures must always be considered, but may not be found. What may appear as adult onset asthma may in fact be a recurrence from childhood--but the person is unaware that childhood symptoms were asthma..
Occupational asthma is caused by an agent inhaled at work. It is thought to affect up to 10% of all people with adult-onset asthma. If the worker is kept away from the offending substance, the asthma may resolve completely, so long as the problem is identified early and appropriate action taken. The longer the exposure continues, the less likely it is that the symptoms will resolve, even if the person eventually leaves that job.