What is asthma?

Asthma is a common chronic lung disease with two main causes: inflammation (swelling and excess mucus build-up in the airways) and airway constriction (tightening of the muscles surrounding the airways). Treating both causes of the disease is necessary for many patients to achieve optimal asthma control and help prevent symptoms.1

What are the main symptoms?

The most common symptoms of asthma are:

  • Shortness of breath
  • Wheezing
  • Chest tightness
  • Cough

Other signs of asthma can include a persistent cough at night; difficulty breathing during, or soon after, physical exertion or exercise; or waking up at night because of one or more of these symptoms.1

Asthma is unpredictable. Asthma symptoms may seem mild or even nonexistent, but they can flare up and be severe at any time. The underlying inflammation of asthma always exists, making preventive treatment important.

Asthma 'at a glance'

  • Around 300 million people worldwide have asthma1
  • It is estimated that there may be an additional 100 million people with asthma by 20252
  • Over half of those with asthma are not well-controlled, leading to unnecessary symptoms and impact on quality of life3
  • It is estimated that asthma accounts for about 1 in every 250 deaths worldwide, many of which are preventable2

Prevalence of asthma in Singapore

  • In Singapore, it is estimated that 140,000 individuals have current asthma and more than 100 individuals die of this disease annually7.
  • The number of asthma cases in children has doubled over the last 15-20 years. Asthma, together with bronchitis and emphysema, accounted for 7 out of every 1,000 deaths in Singapore for the year 20008.
  • One in five children suffer from asthma in Singapore9
  • Controlling asthma

Can asthma be controlled?

GINA, the Global Initiative for Asthma, states that the goal of asthma treatment, to achieve and maintain clinical control, can be reached for the majority of patients.1 This is reinforced by the findings of major international clinical trials such as the Gaining Optimal Asthma control (GOAL) study.6

Two main types of medicines are used to treat and control asthma - relievers and controllers. Relievers are medicines used on an "as needed" basis. They act quickly to open the airways and relieve the immediate symptoms of asthma caused by bronchodilation.1

Controllers are medicines taken daily on a long-term, regular basis to keep asthma under control mainly due to their anti-inflammatory effects.1

What are the signs of not well-controlled asthma?

Asthma that is not well-controlled can put patients at risk for increased asthma symptoms, sudden attacks, hospitalisation and even death. Signs of poor asthma control include1:

  • Experiencing regular symptoms of asthma
  • Waking up during the night because of asthma symptoms
  • Having an asthma attack, being hospitalised or needing other urgent care for asthma
  • Regular need for reliever medications
  • Being unable to maintain normal activity levels, for example, having to miss work or school

Regular assessment of the level of asthma control is vital to ensure patients receive optimal treatment. Increased use of reliever medicines (for example more than twice a week) is a warning that asthma may not be well-controlled and indicates the need to review management, while the ongoing assessment of asthma control with validated questionnaires such as the Asthma Control TestTM is also recommended by GINA.1


1. Global Initiative for Asthma. Global strategy for asthma management and prevention. Updated 2008.

2. Global Initiative for Asthma. Global burden of asthma report. May 2004

3. Desfougeres et al. ERS, September 17th 2007, abstract 1589.

4. Accordini et al. Allergy. 2008. 63 116-124.

5. European Lung Foundation and European Respiratory Society. The European Lung White Book. 2003.

6. Bateman et al. Am J Respir Crit Care Med. 2004;170(8):836-844

7. The Economic Cost of Asthma in Singapore, March 2008. Retrieved from: http://www3.interscience.wiley.com/journal/119939057/abstract

8. Ministry of Health: Guidelines For Better Management Of Asthma By Family Doctors. Retrieved from: http://www.moh.gov.sg/mohcorp/pressreleases.aspx?id=1042

9. Prof Daniel Goh Yam Thiam, NUH "I-CAN!" Programme, "OPTIMISING ASTHMA CARE IN THE CHILD - A BRAND NEWAPPROACH", 28 Oct 2002

Information courtesy of the "I CAN!" programme. "I CAN!" is the first asthma and allergy management programme in Singapore. The University Children's Medical Institute, NUH, is dedicated to the holistic care of children with asthma and allergies. The acronym for the Children's Asthma and Allergy Network is "CAN" - a positive way to say that every child with asthma and allergies CAN lead a totally normal lifestyle while using the least medication.