How often and how severe symptoms are varies from person to person. Even with the same person, the symptoms may vary from time to time. Some people only rarely have mild, short attacks. Others will have mild coughing and wheezing a lot of the time. These symptoms may get worse when the person is exposed to things they are allergic to; when viral infections occur or as a result of exercising. Sometimes crying, screaming or laughing hard may set off the symptoms.
The first signs of an attack are acute bouts of wheezing, coughing or being short of breath or symptoms that slowly get worse until the person has a hard time breathing.
Sometimes with children, an itch on the front of the neck or upper chest maybe a warning sign that an attack is about to happen. Other times, a child's only symptom may be a dry cough, especially at night or when exercising.
The person having an attack may notice a cough, shortness of breath, a feeling of tightness or pressure in the chest and may hear wheezes. The cough during an acute attack usually does not produce mucus.
During an acute attack, a person will have a rapid heartbeat and breathing rate. He or she will prefer to sit upright or lean forward. The person may feel anxious and appear to be fighting for air. A doctor listening to the person's chest will hear wheezes. Coarse whistles or snoring sounds may be heard along with the wheezes. The chest may appear too full with trapped air.
If the bout is severe enough, the person may not be able to speak more than a few words at a time. Over time, the person may get tired and be breathing shallowly and not very effectively. His or her skin may start turning bluish.
As the breathing process fails and carbon dioxide builds up in the blood, the person may become confused or lethargic. A doctor may hear less wheezing because the patient's lungs are filling up with mucus. As he or she gets tired, less oxygen and carbon dioxide are being exchanged, so the lungs sound quieter. This is a sign of a serious breathing problem that can quickly become life threatening.
Causes and Risk Factors
Several factors lead to the blocking of the airways, including:
- Increased secretions
- Infiltration of cells in the walls of the airways
- Peeling of the cells that line the airways
- Spasms of the muscles that line the airways
- Swelling of the mucous linings of the airways
Muscle spasms in the airways used to be considered the leading cause of obstruction to the airways. Now it is believe that inflammatory disease plays a key role, particularly in chronic asthma.
Most people with asthma have airways that close up quickly in response to stimuli. Why this happens it not yet known. It may be due to changes in the lungs. For example, when the cells in the airways peel away, the person loses factors that help relax contractions in the airways. Thickening inside the airways may be another factor.
Factors that affect inflammation may also have an effect on contractions of the air passages, the production of mucus and swelling inside the air passages. Sometimes these factors are released or formed because of allergic reactions. These include histamine and other substances that make the lungs more sensitive.
More blacks die from asthma than whites. It can affect both adults and children.