What is Asthma?

'Asthma - Symptoms, Diagnosis and Treatment of Asthma

Asthma affects more than 25.7 million people in the U.S. A chronic respiratory disease, asthma causes an inflammation of the airways that results in wheezing, shortness of breath, and chest tightness, among other symptoms. When symptoms worsen and the airways constrict even further, a person suffers from an asthma attack—a condition that requires immediate treatment.

Asthma is a chronic respiratory disease that affects more than 25.7 million people in the U.S., 7 million of them children.1 Asthma causes an inflammation and narrowing of the airways, resulting in periods of wheezing, tightness in the chest, shortness of breath, and coughing, which occurs at night or in the early morning.

The disease most often starts in childhood, but can affect people of all ages. Those at the highest risk of developing asthma are young children who wheeze or have frequent respiratory infections that continue past the age of six.3

Allergies, eczema, or parents with asthma are also signs that asthma could develop in children. Occupational asthma can occur in adults who are in frequent contact with chemical irritants, dusts, or fumes.4

People with asthma suffer from inflamed airways, which are very sensitive to a number of irritants. Although each asthma sufferer is triggered by different irritants, the most common include tobacco smoke, dust mites, air pollution, household pets, mold, and physical exercise.5 When these irritants enter the airways, the muscles in the airways tighten and restrict the amount of air that can enter the lungs. An overproduction of mucus in the cells can also narrow the airways further. These symptoms can happen any time the airways are inflamed, sometimes subsiding on their own or with minor treatment.

Symptoms can sometimes become worse than usual and result in an asthma attack, a fairly common occurrence; about half—58.3% of children and 49.1% of adults—of people with asthma had at least once asthma attack in the previous 12 months. Asthma attacks can become severe enough that the airways close so much that the body’s organs do not receive the oxygen they need. Without immediate treatment, a person suffering from a severe asthma attack could die.

Emergency room visits for asthma-related problems is not uncommon. The CDC reported that in 2012, 1.8 million people visited an emergency care facility for asthma, and 439,000 people were hospitalized because of the condition. And the number of people suffering from asthma has only grown—the percentage of the U.S. population with asthma has increased from just 3.1% in 1980 to 8.4% in 2010.6

There is no cure for asthma, but there are plenty of treatment options that include both long-term control and quick-relief medication. The purpose of asthma treatment is to prevent symptoms, maintain lung function, reduce the need for quick-relief medication, prevent asthma attacks, and, perhaps most importantly, allow people with asthma to maintain a normal, active, and healthy lifestyle.

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Additional Diseases Info:

Asthma Infographic


alveolus air sac where gas exchange takes place.
angina chest pain.
aorta blood vessel that delivers oxygen-rich blood from the left ventricle to the body; it is the largest blood vessel in the body.
apex top portion of the upper lobes of the lungs.
atrium one of the two receiving chambers of the heart.
base bottom portion of lower lobes, located just above the diaphragm.
blood pressure pressure of blood against the walls of a blood vessel or heart chamber.
bronchiolitis inflammation that involves the bronchioles (small airways).
bronchoscopy the examination of the bronchi (the main airways of the lungs) using a flexible tube (bronchoscope). Bronchoscopy helps to evaluate and diagnose lung problems, assess blockages, obtain samples of tissue and/or fluid, and/or to help remove a foreign body.
bronchus large airways; lung divides into right and left bronchi.
cardiac output total amount of blood being pumped by the heart over a particular period of time.
catheter thin, flexible medical tube; one use is to insert it into a blood vessel to measure blood pressure.
constrict tighten; narrow.
cyanosis bluish color in the skin because of insufficient oxygen.
diaphragm primary muscle used for respiration, located just below the lung bases.
diastolic pressure lowest pressure to which blood pressure falls between contractions of the ventricles.
dilate relax; expand.
dyspnea sensation of difficulty in breathing.
edema swelling due to the buildup of fluid.
endothelial cells the delicate lining, only one cell thick, of the organs of circulation.
expiration exhaling; giving off carbon dioxide.
heartbeat one complete contraction of the heart.
hyperactive describes a situation in which a body tissue is especially likely to have an exaggerated reaction to a particular situation.
hypertension abnormally high blood pressure.
hypotension abnormally low blood pressure.
inspiration inhaling; taking in oxygen.
lobectomy removal of an entire lobe of the lung.
lung volume the amount of air the lungs hold.
mean blood pressure average blood pressure, taking account of the rise and fall that occurs with each heartbeat. It is often estimated by multiplying the diastolic pressure by two, adding the systolic pressure, and then dividing this sum by three.
palpitation sensation of rapid heartbeats.
perfusion flow.
pleura membrane that covers the outside of the lung.
pneumonectomy removal of an entire lung.
pulmonary artery blood vessel delivering oxygen-poor blood from the right ventricle to the lungs.
pulmonary hypertension abnormally high blood pressure in the arteries of the lungs.
smooth muscle muscle that performs automatic tasks, such as constricting blood vessels.
spirogram record of the amounts of air being moved in and out of the lungs.
syncope fainting; temporary loss of consciousness.
systemic relating to a process that affects the body generally; in this instance, the way in which blood is supplied through the aorta to all body organs except the lungs.
systolic pressure the highest pressure to which blood pressure rises with the contraction of the ventricles.
vasodilator agent that widens blood vessels.
ventilation movement of air (gases) in and out of the lungs.
ventricle one of the two pumping chambers of the heart; right ventricle receives oxygen-poor blood from the right atrium and pumps it to the lungs through the pulmonary artery; left ventricle receives oxygen-rich blood from the left atrium and pumps it to the body through the aorta.