Asthma is a chronic (long-term) disease that causes airways in the lungs to become irritated and inflamed making it hard to breathe. Approximately one in six New Zealanders has asthma, while one in four New Zealand children has asthma. Asthma is one of the most common causes of admission to hospital for children.
Asthma can start at any age but commonly begins in childhood. Many children grow out of asthma by their teens. Others first develop asthma in adulthood. Asthma often runs in families and can be associated with allergic conditions such as eczema and hay fever.
New Zealand has one of the highest rates of asthma in the world. It disproportionately affects Maori and Pacific Island people, and those from lower socio-economic groups. Exposure to certain dusts or chemicals may predispose people to asthma.
Signs and symptoms
Asthma attacks are characterised by difficulty breathing – especially exhaling. The severity of asthma symptoms varies between individuals. A severe asthma attack can be life threatening if treatment is not sought immediately.
Common signs and symptoms of asthma include:
- Coughing – which may worsen at night
- Chest tightness
- Shortness of breath
- Difficulty speaking (in more severe attacks)
- Blueness around the mouth (in more severe attacks).
The exact cause of asthma is not fully understood. It is believed to be caused by a combination of genetic and environmental factors. It is known that most people with asthma constantly have some degree of inflammation in their airways. Their airways are also sensitive to certain irritants, known as triggers. Triggers can cause tightening or constriction of the already inflamed airways, thus provoking an asthma attack. Each individual tends to have different asthma triggers.
Common asthma triggers include:
- Pollens or moulds
- House dust mites
- Air pollution
- Certain foods or food additives
- Strong perfumes
- Cigarette smoke
- Some medicines e.g.: aspirin, non-steroidal anti-inflammatory drugs, beta blockers
- Respiratory infections such as colds and influenza
- Changes in temperature and humidity
- Psychological influences e.g.: extremes of emotion
- Workplace irritants e.g.: paint and varnish fumes, flour, wood and dust.
While asthma cannot be cured, it can be controlled by avoiding triggers and through the use of medications. There are a variety of asthma medications available. Your doctor will be able to discuss which may be most appropriate for you.
The main types of medications used to control asthma are:
These are usually an inhaled corticosteroid medication which has the effect of reducing swelling and decreasing the body’s reaction to triggers. It takes time for preventers to start acting (up to three months of regular use). They are taken on a regular basis each day to prevent symptoms.
These inhaled medications cause the airways’ muscle to relax thus reducing constriction and relieving the symptoms of asthma. They are quick acting and are used to relieve symptoms once they have started.
These are long-acting inhaled relievers and are used in conjunction with a preventer. They work by keeping the airway muscles relaxed and are usually used twice a day. The use of a symptom controller should reduce the need to use a short acting reliever.
Combination inhalers contain both preventer and symptom controller medicine in one device.
Other control methods:
Severe asthma attacks may require hospitalisation to control symptoms. Relieving medication may need to be given using a nebuliser (inhaled in a fine mist of oxygen via a specialised mask or mouthpiece) or intravenously (as an infusion into a drip in the hand or arm). Intravenous corticosteroids may also be given.
Getting a seasonal influenza vaccination will reduce the risk of influenza, which in turn will reduce the risk of serious asthma. People who are on regular preventive therapy for asthma can see their doctor about a free influenza vaccination each autumn.
Other control methods include staying physically fit and avoiding smoking can also minimise asthma symptoms and attacks.