Thomas Gatt from the Malta Medical Students’ Association explains asthma, highlighting symptoms, causes and treatment, mapping out the way our bodies work and how to fight back.
What is asthma?
Asthma is an allergic disease, characterised by inflammation of the airways in the lungs. The combination of the inflammation, airway narrowing (due to muscle contraction) and increased mucus production lead to airway obstruction and the symptoms of asthma.
How common is it?
Asthma is a common disease, which affects an estimated 230 million people, worldwide. It can affect people of all ages, and is especially common in young children and middle-aged females.
What are the symptoms?
These may include:
■ wheezing (a whistling sound produced when breathing outwards);
■ coughing;
■ shortness of breath; and
■ a feeling of tightness in the chest.
They are generally worse at night or early in the morning, and sometimes may occur after a common cold or exercise.
What causes asthma?
It is believed to be due to a combination of environment and genetic factors.
Certain risk factors make a person more prone to having asthma; for instance, a mother smoking during pregnancy increases the chances of an asthmatic child.
Environmental factors which trigger an asthmatic attack may be allergens such as dust, pollen and animal fur, feathers or irritants such as chemicals, smoke or sprays.
Other triggers may include stress, colds or certain types of medication, such as aspirin. It is important to find out what triggers are responsible for an asthmatic attack, so exposure to them can be avoided.
I think I may have asthma. What can I do?
If you think you may be suffering from asthma, consult your doctor.
Generally, your doctor may ask you for a family history and ask questions about your daily environment such as your home and workplace, to determine the cause of asthma.
Your doctor may then carry out a number of physical tests, for example, listening for wheezing sounds through a stethoscope, or carrying out simple breathing tests that measure the power of your lungs.
What are the different types of asthma?
Asthma may be classified as:
■ severe or mild, based on the strength of the asthma attack.
■ persistent (regular) or intermittent (irregular), based on the frequency of attacks.
How can asthma be treated?
Treatment may vary depending on the severity and frequency of asthma attacks.
At the moment, there is no cure for asthma, but it may be controlled. By proper treatment and management of asthma, one may still lead a perfectly normal life.
There are two types of treatment for asthma; the short-term and long-term treatment.
Short-term treatment
Fast-acting treatment (relievers) are used for acute asthmatic attacks. The drugs used are referred to as bronchodilators, because they dilate (widen) the bronchioles.
Typically, the drug used is salbutamol, more commonly known by the brand name Ventolin.
This is inhaled through the mouth (oral inhalation), in the form of a mist.
The medication is stored in a metered-dose inhaler (MDI), a portable device that allows the patient to easily carry the medication with him/her in case of a sudden asthma attack.
Salbutamol targets the tightened muscles around the airways and causes them to relax, allowing air to flow into and out of the lung more easily.
Overuse of inhalers can be extremely dangerous.
Long-term treatment
This is typically prescribed in cases of frequent asthma attacks.
Treatment consists of inhaled corticosteroids, given to prevent the inflammation.
They are given daily to prevent the onset of the attacks, rather than just treating the symptoms.
The drugs given aim to reduce the inflammation and can be used together with long-acting bronchodilators.
How do I treat an acute attack?
1. Take your bronchodilator.
2. If symptoms persist, a doctor should be consulted.
3. Take oral corticosteroids.
4. Use nebulised bronchodilators (a mask which provides you with a higher dose of bronchodilator in mist form).
5. If you still remain breathless, call for an ambulance at once.
How can I control my asthma?
If left untreated, asthma could well lead to permanent lung damage and death. It is important to take control of your asthma by:
■ knowing what your symptoms are;
■ knowing your triggers;
■ limiting your exposure to known triggers;
■ keeping an asthma diary, which includes the date, time, cause and location of each asthma attack;
■ taking your preventer (oral corticosteroids) regularly;
■ going for regular monitoring visits to your doctor or respiratory physician; and most importantly;
■ carrying your inhaler at all times and knowing how to use it!
Asthma should not be taken lightly. It is a serious condition, but with the help of a physician and by taking an active role in asthmatic care, it may be controlled up to a point where one can lead a perfectly normal life.
Airway obstruction
The respiratory tree refers to the branching of the windpipe, all the way down to the small air sacs, which make up the lung. Air enters the mouth and passes through the trachea (windpipe). This then branches into two primary bronchi, supplying each lung. The bronchi further divide into smaller bronchioles, which are the smallest airway tubes in the lung. They end as inflated sacs of air called alveoli.
This diagram represents a cross-section of the airways, which allow passage of air from the environment to the lungs and vice versa. The diameter of the airways, and so the flow of air, is controlled by a layer of involuntary smooth muscle surrounding the airways, which can contract or relax accordingly. However, this diagram represents the airways in an asthmatic person, during an asthmatic attack. Here, cells lining the airways are more prone to inflammation by various triggers, such as dust or pollen. This chronic (persistent) inflammation causes the smooth muscle layer to contract, narrowing the airway and allowing less air to enter or leave the lungs. The cells of the airways secrete mucus to try and protect the lung from further asthmatic triggers. This mucus will lead to increased airway obstruction.