This narrowing is due to:

	Tightening of the muscles around the airways
	Spasm of the muscles that surround bronchial tubes
	Swelling of the lining of the bronchial tubes
	Thick mucus produced by the cells of the lungs

Causes of Asthma

The following factors can be involved:

	Smoking - smoking cigarettes increases the risk of developing asthma
	Heredity - asthma may run in the family
	Allergies - people allergic to pollen and dander are more likely to develop asthma
	Medications - some medications such as blood pressure and heart drugs, aspirin, and sleeping pills can cause or worsen asthma

Symptoms of Asthma

Common symptoms include:

	Tightness in the chest
	Shortness of breath
	Wheezing
	Coughing
	Excess mucous

Triggers

There are a wide variety potential triggers for asthma including environmental pollutants, weather, and strong emotional reactions. The most common triggers of asthma are:

	Cigarette smoke, and wood smoke
	Scented products such as perfume, hairspray, cleaning products and room deodorizers
	Workplace chemicals, dust, and vapors
	Auto exhaust, ozone, sulfur dioxide
	Pollens from grass and trees
	Molds, house dust, mites, cockroaches
	Pet dander
	Colds, influenza, pneumonia
	Vigorous exercise
	Cold drinks
	Menstrual period or pregnancy
	Strong emotional reactions such as crying, laughing, fear, anger
	Environmental changes from moving or traveling
	Changes in weather and temperatures, extreme cold or extreme humidity.

Demographics

	Over 14 million Americans ( nearly 1 in 20) suffer from asthma
	1/2 of the people who suffer from asthma are between 2 and 17 years of age
	1/3 of the people who suffer from asthma are over the age of 30
	More than 1/4 of people over 65 suffers from wheezing and other symptoms associated with asthma.
	More Americans are seeking medical care for asthma--visits to doctors are up 50% in the last decade.
	Over 10.5 million visits to doctors offices are made by people with asthma each year.
	Over 1.5 million visits are made to the hospital emergency departments by patients with asthma each year
	Asthma patients spent an average of 4 days in the hospital each year
	More than 2000 people die each year due to asthma.

Asthma medications fall into two main groups:

	Bronchodialators - medicines that help stop an asthma attack after it has started
	Anti-Inflammatories - medicines that help to prevent asthma attacks.

Bronchodialators

The most highly used bronchodialators are short acting beta 2 adrenergics that are inhaled. They begin to take effect within minutes of taking them and last for 4-6 hours. The most common beta 2 adrenergics available in the U.S. are:

	albuterol
	bitolerol
	isoetharine
	metaproterenol
	piruterol
	raceprinephrine
	terbutaline

Side Effects

	The most common side effects of these beta 2 adrenergics are:
	headache
	muscle tremor
	palpitations
	heartburn
	elevated blood pressure
	nausea
	nervousness
	dizziness

Also in use are long acting beta 2 adrenergics. Their effects begin more slowly, but lasts up to twelve hours. The most common long acting beta 2 adrenergics are:

	salmetrol
	formoterol

Side Effects

The most common side effects of these long acting beta 2 adrenergics are similar to the short acting ones. They include:

	muscle tremor
	palpitations
	elevated blood pressure
	nausea
	nervousness
	dizziness

Anti-inflammatories

The main anti-inflammatories in use today are corticosteroids. These include:

	beclomethasone
	budespnide
	triamcinolone
	acetodide
	flunisolide
	flutinasone

Side Effects

The most common side effects of corticosteroids include:

	hoarseness or loss of voice
	bruising
	dermal thinning
	adrenal suppression
	altered bone yeast infection.