Bronchitis
Bronchitisis an inflammation of the bronchi.Acute bronchitisis usually caused by viruses
or bacteria and may last several days or weeks. It is characterized by a cough that produces
phlegm (mucus). Symptoms include shortness of breath and wheezing, which are related to
the inflammation of the airways. Acute bronchitis is usually treated with antibiotics.
Chronic bronchitismaynotbecausedbyabacteriumoravirus. Chronicbronchitisisdefined
as having a cough that produces phlegm, for at least three months in a two-year period.
Tobacco smoking is the most common cause of chronic bronchitis, but it can be caused by
environmental pollution such as smog and dust. It is generally part of a syndrome called
chronic obstructive pulmonary disease(COPD), which we will learn about later. Treatments
for bronchitis include antibiotics and steroid drugs to reduce inflammation.
Asthma
Asthmais a chronic illness in which the bronchioles are inflamed and become narrow, as
shown inFigure 19.7. The muscles around the bronchioles contract which narrows the
airways further. Large amounts of mucus are also made by the cells that line the lungs. A
person with asthma has difficulty breathing. Their chest feels tight and they wheeze.
Asthmacanbecausedbydifferentthingssuchasexposuretoanallergen. Anallergenisany
antigen that is not an infectious organism. Allergens can cause allergic reactions. Common
allergens that cause asthma are mold, dust, or pet hair. Asthma can also be caused by cold
air, warm air, moist air, exercise, or stress. The most common asthma triggers are viral
illnesses such as the common cold. The symptoms of asthma can usually be controlled with
medicine. Bronchodilatorsare drugs that reduce inflammation of the bronchioles allowing
air through.
Asthma is not contagious and cannot be passed onto other people. Sometimes people with
asthma are afraid that being active could cause them to have an asthma attack. Having
asthma does not mean that you have to miss out on being active. Many teens that have
asthma are active every day. Asthma cannot be cured, but is treatable with medicines.
Children and adolescents who have asthma can still lead active lives if they control their
asthma. Asthma can be controlled by taking medication and by avoiding contact with
environmental triggers for asthma.
Pneumonia
Pneumoniais an illness in which the alveoli become inflamed and flooded with fluid. Pneu-
monia is a restrictive respiratory disease. Gas exchange cannot happen properly across the
alveolimembranes. Pneumonia can be caused bymanythings. Infection bybacteria, viruses,
fungi, or parasites can cause pneumonia. An injury caused by chemicals or a physical injury