Understanding Asthma

What is asthma?

Asthma is a condition caused by inflammation of the small airways in the lung resulting in coughing, wheezing, difficulty breathing, or a combination of all of these. Asthma occurs when the small airways (bronchi) in the lungs become narrow, limiting the flow of air out of the lungs. It is one of the most common chronic diseases in developed countries, especially in children with the condition affecting about 12 percent of those less than 18 years of age.

The symptoms of asthma occur periodically, often due to specific triggering events. The airways of an asthmatic patient are sensitive to a variety of stimuli, which may include viral illnesses (e.g. the common cold), pollen, foods, or environmental conditions. In addition, many different genetic and environmental factors can increase the risk of developing asthma. These factors include:

  • Exposure to tobacco smoke — Exposure to tobacco smoke during pregnancy and throughout childhood increases the risk of developing asthma.
  • Family history — Children with a personal or family history of certain medical problems, such as asthma or eczema, are at increased risk of developing asthma.
  • Pollution — Increased exposure to indoor and outdoor pollution may heighten the risk of developing asthma.

However, not all people with asthma have known risk factors. Even people who live in rural areas and children with parents that don’t smoke or don’t have a history of asthma can develop it. While scientists are looking for answers, it is still not clear if there are ways to reduce a child’s risk of developing asthma.

What are the symptoms?

Most people are aware of wheezing as a symptom of asthma. Wheezing is a high-pitched noise that is heard when breathing out. However, another common symptom of asthma in children and adults is coughing, often with but also sometimes without any wheezing. The cough is usually dry and hacking, and is most noticeable while sleeping and during the early morning hours, or after exertion. These symptoms are usually intermittent during the day and night, depending on the severity of the asthma. In more severe cases of asthma, breathlessness and chest tightness may also occur.

Asthma symptoms can develop at any age, but it is most common for the symptoms to first present in children before five years of age. The good news is that many children who are diagnosed with asthma “grow out” of their condition; Studies show that 30 to 70 percent of children with asthma are markedly improved or have no signs of asthma by early adulthood.

What are some asthma triggers?

Most asthma attacks develop slowly over a period of several days. Although uncommon, severe attacks can occur suddenly and with little warning. Wheezing and coughing may occur at any time, but certain triggers are known to worsen asthma in many children.

Environmental conditions

Asthma symptoms may worsen during certain pollen seasons, such as during tree pollination time in early spring. Another trigger might come when grass grows in late spring and summer, or during weed growth in the summer and fall. Mold, which often grows during rainy seasons, can also trigger asthma. Any or all of these may mix with seasonal allergy symptoms to increase the chance of triggering and heighten the severity of asthma. Cold air, changes in barometric pressure, rain, or wind may also cause increased asthma symptoms in some people. While increased exposure to indoor and outdoor pollution as well as cigarette smoke may increase the risk of developing asthma.

Upper respiratory infections

Viral upper respiratory infections, such as head and chest colds, are a very common trigger of asthma in infants and young children. The most common viral infections include rhinovirus–the virus that causes most colds, respiratory syncytial virus, and influenza virus. In most cases, children with asthma should use doctor prescribed asthma treatments for cough and chest congestion, rather than over-the-counter cold remedies, to ensure effective treatment. It is also important for a physician to frequently review treatment plans so that adjustments can be made for a variety of factors, such as the seasonal conditions described above.


Narrowing of the airways can be triggered by exercise. This is called “exercise-induced asthma.” Breathlessness, wheezing, and/or coughing usually occur within five to ten minutes of the cool-down period after vigorous exercise. These symptoms tend to disappear after 20 to 45 minutes. Certain types of exercise, like swimming, are less likely to cause exercise-induced asthma than activities like running or skating. This is likely because some exercises like swimming produce fewer airway cooling and drying.


Indoor and outdoor allergens are an important trigger of childhood asthma, particularly for children older than three years of age. These include:

  • House dust, produced by things like dust mites, cockroaches, and mice droppings
  • Animal exposures, especially to furry animals like cats, dogs, gerbils, rabbits, or hamsters
  • Indoor pollutants, often with chemical pollutants, such as paints, perfumes, and room deodorizers, yet space heaters and gas stoves can also add to allergies that trigger asthma.
  • Pollens
  • Molds

If allergies are a possible cause of symptoms, testing the skin or blood for reactions to a range of allergens may be recommended. This can help to both identify triggers and determine the necessity of avoiding these triggers at home.


Emotions do not cause asthma but can make asthma worse. Patients with asthma often find that in times of stress their symptoms are worse.

How is asthma diagnosed?

Diagnosis of asthma can be made only after a careful review of an individual’s current and past medical history, family history, and a physical examination. Specialized testing, such as spirometry, is sometimes needed to diagnose asthma and to rule out other possible causes of symptoms.

Spirometry measures the flow and volume of air generated after taking a very deep breath, and then after forcefully blowing all the air out of the lungs. It is the most accurate way for testing resistance to airflow in the small airways of the lung, but it is not usually performed on children under the age of six years, since it is often difficult for them to conduct the test properly. In such cases a doctor may recommend a light trial treatment to confirm the diagnosis. In some children, skin or blood testing for allergies may be recommended.

What treatments are available?

Symptoms and severity of asthma can fluctuate from time to time. As a result, successful management of asthma requires close collaboration between you and your doctor to best monitor your condition, or that of your child. This is done by recording the frequency and severity of symptoms like coughing, breathlessness and wheezing. Based on the severity and frequency of these symptoms, you and your doctor should develop an asthma management plan together. This plan not only guides the current treatment, but also decides what to do should the severity of symptoms change.

Medications used to treat asthma vary and are tailored to each individual. There are three basic groups of medications used for the treatment of asthma. These include:

  • Relievers — Work rapidly to open the airway and have short term benefit by relieving the symptoms
  • Symptom controllers — Reduce the frequency of symptoms
  • Presenters — Work slowly to control the inflammation and deals more directly with the underlying problems

Where can you get more information?

Your doctor is the best source of information for questions and concerns related to this medical problem. Because no two patients are exactly alike, and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with you or your child’s situation.