Everything You Need To Know About Asthma

At a glance:

• Asthma is a chronic medical condition that causes the airways to swell or narrow, causing difficulties with breathing
• Depending on the triggers and other factors, asthma may be categorised in a number of different ways, including: adult onset asthma, exercise-induced bronchoconstriction, allergic asthma and occupational asthma
• Asthma is the most common childhood disease in Australia, with around one in six children having some form of asthma
• Around 2.2 million Australians have some form of asthma

What is Asthma?

Asthma is a chronic medical condition that causes the airways to swell or narrow, causing difficulties with breathing. For some, the symptoms of asthma may be a minor nuisance and be triggered by very specific circumstances or factors, but for others asthma may be a life changing and serious condition.

Depending on the a number of different factors, asthma may be categorised in a number of different ways, such as:

1. Adult Onset Asthma - asthma that shows no signs or symptoms until the person reached adulthood.
2. Allergic Asthma - asthma that is triggered by exposure to allergens, such as pet dander, dust or pollen.
3. Exercise-Induced Bronchoconstriction (EIB) - EIB used to be referred to as Exercise Induced Asthma. People with EIB experience a narrowing of their airways after physical exertion. Around 90% of people with other forms of asthma also have EIB but not everyone with EIB has another form of asthma.
4. Nocturnal Asthma - breathing difficulties that worsen at night. This may involve allergies, such as dust mites in pillows or mattresses, heartburn or gastroesophageal reflux, or other sleep problems.
5. Non-Allergic Asthma - narrowing of the airways triggered by things other than allergens, such as stress, weather, temperature or illness. 
6. Occupational Asthma - breathing difficulties triggered by airborne irritants found in workplaces, such as chemical fumes or industrial dust.

Mechanically, a number of different things can happen inside the airways to cause the symptoms of asthma. The airways contain a thin layer of muscle. When this muscle tightens and contracts, the airway becomes narrower, making breathing more difficult.

The lining of the airways may also become irritated and inflamed. This inflammation narrows the airways, limiting the amount of air that can pass through. Finally, irritated tissue may also produce excess mucus, constricting the airways. 

Any of these individual effects may cause the symptoms of asthma, or they may occur in combination during an asthma flare-up.

An asthma flare-up (sometimes referred to as an asthma attack) is when symptoms become more severe and require treatment to lessen. Flare-ups due to contact with a trigger, such as an allergen or a period of intense exertion typically come on fast, but if the cause is an illness the symptoms may worsen over an extended period of time.

Flare-ups may become serious if not treated early and may require the attention of a medical professional if symptoms become too severe.

Asthma is a very common condition in Australia, with around 2.2 million people living with some form of the disease. It is the most common childhood disease in the country, with around one in six children and one in seven adolescents being diagnosed with asthma.  

Symptoms of Asthma

The symptoms of asthma may vary from person to person in presentation, severity and duration. The type of asthma a person suffers may also be reflected in the way asthma presents. Common symptoms include:

• Shortness of breath
• Wheezing when inhaling or exhaling. This is often one of the first symptoms readily noticeable in children
• Chest pain or tightness
• Discomfort in the throat or upper chest
• Coughing fits
• Having a pronounced and lasting cough or wheeze when ill with a virus, such as the common cold 
• Difficulty falling asleep or broken sleep due to shortness of breath, wheezing or coughing

Depending on the type of asthma, symptoms may become more pronounced or severe in certain situations, such as:

• Exercise-Induced Bronchoconstriction (EID) - In addition to being triggered by exertion, EID may also be exacerbated or triggered by cold or dry air.

• Allergic Asthma - a person with allergic asthma may have multiple triggers for the condition, some more severe than others. A person with an allergy to pet dander may also be triggered by pollen, cockroach waste, dust or the like to a greater or lesser degree. 

Asthma may become more serious with time due to exposure to irritants, genetics, lifestyle or poor asthma management. Signs that your asthma may be worsening include:

• Having more frequent asthma attacks or needing to use your inhaler more frequently
• Breathing difficulties become more pronounced
• Your lung capacity and strength (tested by a doctor with a peak flow meter) is low

Due to a similarity in symptoms, such as wheezing, coughing and shortness of breath, Chronic Obstructive Pulmonary Disease (COPD) may be misidentified as asthma and vice versa. COPD is a blanket term for a number of respiratory diseases, including chronic bronchitis and emphysema . 

The major point of difference between asthma and COPD is that there is no real known cause for asthma, whereas around 90% of COPD can be directly traced to smoking. The ages of diagnosis typically differ as well, with the majority of people with asthma being diagnosed as children, whereas the typical age at which COPD is diagnosed is over 40.

That said, around 40% of people with COPD also exhibit signs of asthma, due in part to both COPD and asthma becoming more common with age.

If you or your child experience difficulties breathing after exertion or because of allergies, you may need to see a doctor to be tested for asthma .

What Causes Asthma?

There is no exact cause of asthma currently known. Genetics appears to play a part, with people with a family history of asthma being more likely to have asthma than people without. 

There also seems to be a correlation between a mother smoking while pregnant and a child developing asthma. Children exposed to cigarette smoke, industrial pollution, mould, or those born premature or with a low birth weight also appear to be more at risk of developing asthma.

Cigarette smoking may be a cause of adult onset asthma and obesity has shown to increase instances of asthma.  

One theory known as the “hygiene hypothesis” postulates that modern society has become too clean, meaning that people aren’t exposed to many germs as a child. As a result the immune system may not be able to fight off the development of allergic disorders like asthma. 

While there are no definitive causes known for asthma, it is most likely caused by a complex interaction of genetics and environmental factors. As such, there are a few recommendations when it comes to reducing the risk factors for developing asthma, the most important of them being, don’t smoke while pregnant or around children.

If you’re currently in lockdown or self isolating, you can make an appointment with the Virtual Respiratory Clinic for a consultation from the comfort of your home. 

Living With and Treatment For Asthma

In Australia, treatment for asthma is based around the 6 Step Asthma Management Plan created by the National Asthma Council Australia . As the name suggests, this plan is broken into the following six steps:

1. Assessment - a doctor will first assess the seriousness of the asthma through testing. The asthma may be described as mild (the majority of cases), moderate or severe (only around 5%-10% of cases are severe).
   
2. Achieving Lung Function - there are a number of medications used to control asthma symptoms so there may be a period of testing different medications to see which offers the best symptom management. The doctor may also test different dosages to find the optimal medication and dose.
   
3. Identifying Triggers - identifying the factors that trigger asthma symptoms or flare-ups allows you to better avoid them or mitigate their presence. Identifying triggers may involve allergy prick tests or keeping a symptom diary.
   
4. Maintaining Lung Function - the doctor will create a long term medication plan. This will typically revolve around a preventer and a reliever, the former being for daily use and the latter to manage flare-ups.
   
5. Asthma Action Plan - your doctor will help you put together an asthma action plan that will help you monitor the progress of your asthma and courses of action that may be required. This action plan may also involve lifestyle changes to limit triggers or risk factors.  
   
6. Reviews - even if your asthma is mild, having regular reviews of your lung function will allow the doctor to change medications or action plans if needed and chart the course of your asthma.

The most common asthma medications are preventers and relievers. Preventers are used regularly to prevent the type of bronchial irritation or hyperactivity that leads to an asthma flare. Corticosteroids are the most common form of inhaled preventers.

Relievers are typically bronchodilators. These inhaled drugs help relax the muscles in the airways to relieve constriction.