Asthma is a chronic lung illness, inflammation of the airways. Asthma causes recurring periods of wheezing (a whistling sound when you breathe), chest constriction, shortness of breath, and coughing. The breathing problems often occurs at night or early in the morning.
Asthma can affect to all people, often starts during youngsters. In America, more than twenty six million people are known to have asthma. About seven and a half million of these are young people.
To understand asthma, it helps to know how the airways work. The airways are tubes that carry air into and out of your lungs. People who have asthma have inflamed airways. The inflammation makes the airways swollen and very sensitive. The airways tend to react strongly to certain inhaled substances.
When the airways react, the muscles them tighten up, causing less air to lungs. The inflammation also can become worse, making the airways even smaller. Cells inside airways might make more mucus than usual. Mucus is a sticky, thick liquid that can further narrow the airways.
1. Airway obstruction.
The muscle that surround the airways are relaxed, through regular breathing and air moves easily.
People with asthma, allergy-causing substances, colds and respiratory viruses, and environmental triggers the muscle surrounding the airways tighten, and air cannot move freely.
Less air causes a person to feel short of breath, and the air moving out through the tightened airways causes a whistling sound known as wheezing.
People with asthma have red and swollen bronchial tubes. This redness is assumed to contribute greatly to the long-term damage that asthma can cause to the lungs. And, therefore, treating this inflammation is key to managing asthma in the long run.
3. Airway irritability.
The airways of people with asthma are extremely sensitive. The airways tend to overreact and narrow due to even the slightest triggers such as pollen, animal dander, dust, or fumes.
Longitudinal studies suggest that susceptibility to childhood asthma is determined during fetal development and in the first three to five years of life. A number of possible risk factors have been suggested for the development of asthma including the following:
Family history of allergy and allergic disorders (including hay fever, asthma and eczema);
High exposure of susceptible children to airborne allergens (pets, house dust mites, cockroaches, mould) in the first years of life;
Exposure to tobacco smoke, including in utero exposure
Frequent respiratory infections early in life
Low birth weight and respiratory distress syndrome (RDS).