Causes and Symptoms of Asthma

What is Asthma

When an asthma attack occurs, mucus production is increased, muscles of the bronchial tree become tight, and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound. A.D.A.M

What is Asthma?

Asthma is a chronic lung disease, which cannot be cured, yet can be well-controlled with close follow-up with a physician and appropriate medical therapies. In people with asthma, lung airways become inflamed, leading to narrowing of the airways. The muscles around the airways become more sensitive, and can react to allergens and irritants. Asthma can be a life-threatening disease, and there are typically a few thousand deaths in the United States every year as a result of this disease.

What Are the Symptoms of Asthma?

The most common symptoms of asthma include wheezing (a high-pitched squeaking sound occurring during breathing in and out), a sensation of chest tightness or heaviness, a sense of not getting enough air, and coughing. Not all people with asthma will have all of these symptoms. Many people with asthma may only have a cough – this type is termed “cough-variant asthma”.

What Happens During an Asthma Attack?

In a person with asthma, the lining of the airways is swollen and produces more mucus than normal. This can lead to the muscles around the outside of the airways to constrict and narrow the airways. Air has a more difficult time getting in and out of the lungs, which causes the symptoms of asthma.

What Causes Asthma?

Like allergies, the tendency to develop asthma runs in families. If a person has a mother with asthma, or the mother smoked during the pregnancy, then that person has a higher risk for asthma.

People with allergic rhinitis have about a 1 in 4 chance of developing asthma.

Some types of respiratory tract infections, especially if occurring during infancy, place a person at increased risk of developing asthma. Environmental triggers, including allergens and other irritants, can influence the development of asthma.

There is probably not a single cause for asthma, but rather an interaction between a person’s genetic makeup and environmental triggers.

What Triggers Asthma?

The most common trigger of asthma is a respiratory tract infection. In adults, it is the common cold virus. In children, RSV (respiratory syncytial virus) is the common culprit.

Other common triggers include allergens and irritants. The most common allergens include environmental allergens such as pollens, animal dander, dust mite and molds. Food allergies may also trigger asthma symptoms, and may lead to anaphylaxis. Irritants, such as smoke and strong odors, can also trigger asthma symptoms.

The majority of people with asthma will have symptoms worsen with exercise and strenuous activity. However, the term “exercise-induced asthma” is overused and usually applies only to a small group of asthmatics.

Strong emotions, such as laughing and crying, as well as emotional stress, can also trigger the symptoms of asthma.

How is Asthma Controlled?

One of the most important aspects of controlling asthma is the ability to recognize when asthma is just starting to get worse, and treating these symptoms. Therefore, it is also important to know which asthma medication to use at the right time.

Early treatment of an asthma attack usually resolves the problem and prevents asthma from continuing to get worse. An asthmatic should also notify his or her doctor if their asthma symptoms are starting to worsen.

Avoidance of allergic triggers (such as dust mites, pet dander and mold) as well as irritants (such as cigarette smoke, strong odors) can prevent worsening asthma symptoms in those people sensitive to these allergens. And, since the nose and lungs are both part of the respiratory tract, good control of allergic rhinitis will help to control asthma symptoms.

What are the Goals of Asthma Treatment?

The goals of asthma treatment are for an asthmatic to essentially be able to live as if they did not have asthma.

These include:

To be active in sports and exercise with minimal to no asthma symptoms

To avoid severe asthma attacks that lead to emergency room visits and hospital stays

To sleep through the night without asthma symptoms

To have normal lung function as measured in the doctor’s office

To avoid side effects from asthma medications

Remember, these are goals, and many asthmatics may never achieve these. However, with close follow-up with a physician, or with a referral to an asthma expert (such as an allergist), and if a person follows the directions of the physician, these goals should be able to be achieved.

What Medications Are Used to Treat Asthma?

In general, there are 2 types of asthma medications: rescue and controller medicines. Most asthmatics require both medications. Many people with asthma are under-treated with only a rescue inhaler, which is a common mistake for physicians to make. Find out if your asthma is controlled, or if you might need additional therapy (such as a controller medicine).

Rescue medicines are those medicines that are taken as needed. This means that these medicines should be carried with the person with asthma, since an asthma attack can never be predicted. Rescue medicines help relax the muscle around the airways for a few hours, but do not help the inflammation and swelling of the airways. Frequent use of a rescue medicine is a sign that asthma is not controlled.

Controller medicines are those medicines that are taken every day (sometimes multiple times a day) regardless of asthma symptoms. These medicines are taken all of the time in order to control the inflammation and swelling of the airways. This leads to less irritation and constriction of the muscles around the airways and therefore less asthma symptoms. These medicines usually take a few days to a few weeks in order to start working, but then a person with asthma notices that less and less rescue medicine is needed.

What are Examples of Rescue and Controller Medicines?

Examples of rescue medicines include:

  • ProAir (albuterol)
  • Proventil (albuterol)
  • Ventolin (albuterol)
  • Maxair (pirbuterol)
  • Alupent (metaproterenol)

Examples of controller medicines include:

  • Inhaled steroids {Pulmicort (budesonide), Flovent (fluticasone), Advair (fluticasone/salmeterol combination), Azmacort (triamcinolone), QVAR (becloomethasone) and Asmanex (mometasone)}
  • Long-acting beta-agonists {Foradil (formoterol), Serevent(salmeterol)}
  • Leukotriene blockers (Singulair (montelukast), Accolate (zafirlukast), Zyflo (zilueton)}.
  • Theophylline (Theodur, Theo-24, Uniphyl, generics)
  • Mast cell stabilizers {Tilade (nedocromil), Intal (cromolyn)}
  • Xolair (omalizamab)

How Do I Know When My Asthma Inhaler is Empty?

It is easy to calculate how long a controller medicine inhaler will last: for example, Flovent inhalers contain 120 puffs. If your doctor has prescribed 2 puffs to be inhaled twice a day, then you will use 4 puffs a day. 120 divided by 4 is equal to 30. The canister will last 30 days.

In the case of a rescue inhaler, such as albuterol, most canisters have between 100 and 200 puffs. Since these medicines are only used “as needed”, how long a canister lasts depends on how much a person uses the medicine. Once the canister seems to be less than half-full with shaking the device, it is probably time for a new one.

Keep in mind that an inhaler will continue to spray propellant long after the medicine has run out. It is common for asthmatics to continue to use the inhaler, which no longer contains medicine, until their asthma worsens and requires a doctor visit. Always make sure your asthma medicines are in good supply and not past the expiration date.

What are some DOs and DON’Ts of Asthma?


  • Use your medicines as prescribed.
  • See your doctor for “healthy” appointments twice a year, more often if needed.
  • Get a flu shot each year.
  • See your doctor early with cold and flu symptoms.


  • Don’t use tobacco products, which can worsen asthma symptoms
  • Don’t let heart-burn symptoms go untreated, which can also worsen asthma.
  • Don’t use “over-the-counter” asthma medicines (such as Primatine Mist).
  • Don’t use your rescue medicine more than twice a week without telling your doctor.


  1. 1. Practice Parameters for the Diagnosis and Treatment of Asthma. J Allergy Clin Immunol 1995;96:S707-870.
  1. 2. National Asthma Education and Prevention Program Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma. NIH Publication No. 97-4051. 1997/EPR-2 Update 2002.

DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.

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