Asthma causes swelling and inflammation in the airways that lead to your lungs. When asthma flares up, the airways tighten and become narrower. This keeps the air from passing through easily and makes it hard for you to breathe. These flare-ups are also called asthma attacks or exacerbation.
Asthma affects people in different ways. Some people have asthma attacks only during allergy season, or when they breathe in cold air, or when they exercise. Others have many bad attacks that send them to the doctor often.
Symptoms of asthma can be mild or severe. You may have mild attacks now and then, or you may have severe symptoms every day. Or you may have something in between. How often you have symptoms can also change. When you have asthma, you may:
- Wheeze, making a loud or soft whistling noise when you breathe in and out.
- Cough a lot.
- Feel tightness in your chest.
- Feel short of breath.
- Have trouble sleeping because of coughing or having hard time breathing.
- Quickly get tired during exercise.
Symptoms may be worse at night.
Severe asthma attacks can be life-threatening and need emergency treatment.
What Causes Asthma?
Asthma can be caused by extrinsic or intrinsic factors.
Extrinsic (external) factors include:
- Allergies (allergens) are common in children and adults and are a common cause of asthma. Some examples of allergens include inhaled materials, ingested materials (e.g. foods), and materials that cause problems when they contact the skin. Inhaled allergens are some of the most common causes of asthma (e.g. aspirin).
- Occupational asthma occurs in about 10% of asthmatics and results from exposure to offending dusts, gases, fumes, and vapours that are present in the workplace. These materials are high molecular-weight compounds and low molecular-weight compounds.
- Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) can cause asthma in sensitive patients. This problem usually takes time to develop and is characterized by aspirin sensitivity, nasal polyps, and asthma.
Intrinsic (internal) factors include:
- Respiratory infections, especially viral infections, are very common causes of exacerbation of asthma.
- Exercise can induce an asthmatic attack and is called exercise-induced asthma (EIA). Exercise usually induces an increase in respiratory rate and depth of breathing and increases the inhalation of atmospheric air which is cooler than the body temperature air in the lungs. This cooler air appears to stimulate receptors in the lung in susceptible patients to induce bronchospasm and an asthmatic attack.
- Genetic factors have been proposed as causes of asthma. The ADAM-33 gene sets on the short arm of chromosome 20 and has been significantly associated with asthma, being called the asthma gene. Four other asthma genes or gene complexes have been identified with the use of positional cloning.
- Emotional factors and in particular stress have been suspected to cause asthma, but the data to support this is not complete.
Asthma should never stop you from doing the things you want to do. It is important to work with your doctor/provider and follow your care plan so you can enjoy the benefits of exercise without asthma symptoms.