What is Asthma? Understanding Asthma

As asthma is a common disease, most people are aware that it is a condition that affects the lungs. Asthma is a chronic illness—once a person has it, they will have it throughout their life, through periods of remission where they are asymptomatic do occur.

The main symptoms of asthma are coughing, chest tightness, wheezing (a whistling sound when exhaling), and dyspnea—also known as shortness of breath.

What Causes Asthma Symptoms?

The cause of asthma itself is not known, but it is thought to have environmental and genetic causes [1].

Asthma symptoms are caused by inflammation and constriction in the airways of the lungs. Underlying inflammation is continuously present in asthma that is not treated [2]—the combination of inflammation and constriction of the muscles surrounding the airways causes airways to narrow, making it more difficult to breathe. During an asthma attack or flare-up, this muscle constriction and production of extra mucus further narrows airways, causing asthma symptoms. [3]

What Triggers Asthma Symptoms?

Asthma symptoms are caused by exposure to what are called “triggers.” Triggers fall into two categories: allergic (or extrinsic) and non-allergic (or intrinsic). [4] Asthma triggers are individual to each person, so what triggers one person’s asthma may not be an asthma trigger for another person. Some people have only one asthma trigger, like exercise or viruses, and others may have a long list of allergens and other triggers.

Allergic triggers include allergens most of us are aware of—pollen, grasses, molds, and dust. Non-allergic triggers include exercise, colds/viruses, chemicals such as perfumes or cleaners, weather like cold air or humidity, smoke and stress. [4]

It is important to avoid triggers when possible, such as cigarette smoke and animal dander (if you are allergic to it). Some triggers may not be avoidable, and in these situations, it is essential to have an Asthma Action Plan created by your doctor to help manage asthma symptoms with medications.

How is Asthma Treated?

There is no cure for asthma, but it can be treated. Medications are used to treat the underlying inflammation in the airways, as well as to relieve the constriction of muscles surrounding the airways. [5] Other treatments include medications that deal with the allergic components of asthma, and newer treatments that work on different pathways specific to your asthma—these are called biologics and are most often reserved for severe asthma that is resistant to other treatments.

If asthma is not treated, permanent scarring can develop causing lung damage. [5] This damage not only makes asthma symptoms worse but also can affect how well you respond to treatment. It is important to take control of your asthma to avoid long-term lung damage.

Who Gets Asthma?

Depending on where you live, between 8 and 10 percent of the population may have asthma [6][7]. While asthma often develops in childhood, it can develop at any age. If you have close relatives with asthma, eczema or allergies, you may be more likely to get asthma yourself.


Asthma cannot be prevented, but it is very treatable. If you think you have asthma, speak with your doctor. They can do breathing tests to determine if you do have asthma. If you have been diagnosed with asthma, you’re in good company—alongside professional musicians, elite Olympic athletes, and many other people you probably know well! Asthma is not always easy to deal with, but once you can take control of asthma, it does not have to control your life!

Every person’s asthma is different, and not everyone experiences the same symptoms. Wheezing is the most easily recognized symptom of asthma, but there is an argument that a cough is the most common. Other symptoms include shortness of breath or chest tightness.

Many people have combinations of these asthma symptoms, and others may have only one or two. Symptoms may also change over time, for instance, a person who previously had only wheezing and chest tightness, may go on to develop coughing and/or shortness of breath as symptoms.

Understanding Asthma - Symptoms and Treatment


Wheezing is most often cited as the most common symptom of asthma. [8] Wheezing is a whistling noise that is audible when exhaling, in some cases, it may only be audible via a stethoscope when a doctor or nurse listens to your lungs. [9]


Cough is the most common reason people seek medical attention each year. [10] While a cough can accompany other asthma symptoms, cough variant asthma is a type of asthma where a cough is the only symptom a person may have. [11] Often, cough is dry [12], but it can be productive in some cases.

Chest Tightness

People describe chest tightness many ways, including feeling as if a resistance band has been tightened around their chest, or as if something heavy is upon their chest. Chest tightness may develop due to the tightening of muscles around the airways, but some research indicates other components of bronchospasm within the airway may contribute to the sensation of chest tightness. [13]

Shortness of Breath

Also known as dyspnea, the subjective sensation of being short of breath as it varies between each patient can be difficult to explain. It may feel as if you are trying to breathe through a straw, and that you cannot get air efficiently in and out of your lungs. This may be due to a problem called “air trapping,” in which the bulk of air is not able to be exhaled from the lungs. [14]

Changes in Asthma Symptoms

As mentioned, asthma symptoms may change over time, and even from one day or attack to the next. Symptoms can range from mild, which resolve within a few hours, to severe enough to require emergency medical treatment. Having an asthma action plan created by your doctor can help ensure you know how to assess your symptoms, and respond appropriately.

Treatment of Asthma

Treatment for asthma targets the main causes of asthma symptoms—inflammation of the tissues lining the airways and constriction of the smooth muscles around the airways.

Rescue (or reliever) medications are those that are taken only when you have asthma symptoms. These medications work quickly to relieve symptoms, usually within 15 minutes, and last for about 4 hours. Ventolin (salbutamol/albuterol), Xopenex and Bricanyl are examples of short-acting rescue medications. These medications are most often taken by metered dose inhaler or dry powder inhaler, but can also be taken by nebulizer as prescribed by a doctor.

The right medications for you depend on many things — your age, symptoms, triggers and what works best to keep your asthma under control.

Most people will need an daily controller (or maintenance) medications, usually an inhaled steroid—a corticosteroid which fights inflammation—which keeps inflammation under control. Flovent, Pulmicort, Qvar, and Alvesco are examples of these kinds of medications.

Inhaled steroids lead to:

  • Better asthma control
  • Fewer symptoms and flare-ups
  • Reduced need for hospitalization

A long-acting bronchodilator is sometimes combined inhaled steroid to keep asthma symptoms under control. Long-acting bronchodilators are most often prescribed in a combination inhaler with inhaled corticosteroids, such as in Advair, Symbicort, and Dulera.

In some cases, another medication called an anti-leukotriene, or leukotriene receptor antagonist (LTRA) is used, which helps to block a pathway responsible for allergic responses and mucus production—one of these medications, and the most common, is called Singulair. Unlike most other medications, LTRAs can be taken as a pill. A person’s response to LTRAs is very individual—they are not entirely effective for all people.

Asthma management is different for everyone, and different people have different preferences about their treatment and devices used, as well as which medications work for them. It may take trial and error to figure out which medications are best for your asthma.

The information on this page is not intended to be a substitute for professional medical advice, diagnosis, or treatment. For more information about asthma, talk to your doctor or primary care provider.

Related Respiratory Information


Updated: December 20, 2018

[1] Mukherjee, A. B., & Zhang, Z. (2011). Allergic Asthma: Influence of Genetic and Environmental Factors. Journal of Biological Chemistry, 286(38), 32883–32889. https://www.ncbi.nlm.nih.gov/pubmed/21799018
[2] Murdoch, J. R., & Lloyd, C. M. (2010). Chronic inflammation and asthma. Mutation Research, 690(1-2), 24–39. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2923754/
[3] Partners Asthma Center. What Is Meant by Inflammation in Asthma? http://www.asthma.partners.org/NewFiles/Inflammation.html
[4] Allergy, Asthma & Immunology. Asthma Overview. https://acaai.org/asthma/about
[5] Global Initiative for Asthma. Guide for Asthma Management and Prevention. Last updated: 2016. https://ginasthma.org/wp-content/uploads/2016/05/WMS-GINA-2016-main-Pocket-Guide.pdf
[6] Centers for Disease Control and Prevention [CDC]. Asthma. https://www.cdc.gov/nchs/fastats/asthma.htm
[7] WebMD. Asthma Symptoms. Last reviewed: July 09, 2018. https://www.webmd.com/asthma/guide/asthma-symptoms
[8] American College of Allergy, Asthma, and Immunology. Asthma Symptoms & Diagnosis. https://www.aaaai.org/conditions-and-treatments/asthma
[9] Medline Plus. Breath Sounds. https://medlineplus.gov/ency/article/007535.htm
[10] Prabhudesai P. (2014). Chronic Dry Cough in Allergic Respiratory Diseases: Diagnostic and Management Approach. Indian Journal of Clinical Practice, 24(11).
[11] American College of Allergy, Asthma, and Immunology. Asthma cough. https://acaai.org/asthma/symptoms/cough
[12] WebMD. Asthma symptoms. Last reviewed: July 09, 2018 https://www.webmd.com/asthma/guide/asthma-symptoms#1
[13] Binks, A. P., Moosavi, S. H., Banzett, R. B., & Schwartzstein, R. M. (2002). “Tightness” sensation of asthma does not arise from the work of breathing. American journal of respiratory and critical care medicine, 165(1), 78-82.
[14] Tunon-de-Lara, J. M., Laurent, F., Giraud, V., Perez, T., Aguilaniu, B., et al. (2007). Air trapping in mild and moderate asthma: effect of inhaled corticosteroids. Journal of allergy and clinical immunology, 119(3), 583-590.

About Kerri M: Kerri is a blogger, coach, quantified self-er, and ePatient. A former gym class hater, she now holds a Bachelor of Physical and Health Education. Diagnosed with asthma in 2008 when she was 16, Kerri believes she is not defined by her diagnoses, but rather that they help explain her. Kerri writes for work and fun (often simultaneously!) on topics including asthma, ADHD, learning issues, patient engagement, and technology. Airplanes, t-shirts and cupcakes are among her favorite things.

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