Haze can contain fine particles and gases that irritate the eyes and airways and may strain the lungs and cardiovascular system. Monitoring Malaysia’s Air Pollutant Index and reducing exposure can help protect you and your family.
Haze is a recurring environmental health concern in Malaysia, particularly during dry periods and episodes of regional smoke pollution. While it may appear to be little more than reduced visibility or a smoky sky, haze can affect more than outdoor conditions.
Understanding haze health risks in Malaysia is particularly important for children, older adults, pregnant women, outdoor workers, and anyone living with asthma, chronic obstructive pulmonary disease (COPD), heart disease or another long-term medical condition.
Knowing the warning signs, checking the Air Pollutant Index (API) and reducing exposure can help prevent mild irritation from developing into a more serious health problem.
What Is Haze and Why Can It Affect Your Health?
Haze occurs when suspended particles and pollutants accumulate in the air. Common contributors include smoke from forest or peat fires, open burning, industrial emissions and vehicle exhaust. During regional haze events, smoke can travel long distances before reaching Malaysia.
The health concern is not simply the air’s smell or appearance. PM2.5 refers to fine particles with a diameter of 2.5 micrometres or less. These particles can travel deep into the lungs, and some may enter the bloodstream, contributing to inflammation and effects beyond the respiratory system.
The World Health Organization identifies particulate matter as a major air pollutant associated with respiratory and cardiovascular harm.*
What Determines the Level of Risk?
The severity of haze-related health risks depends on the concentration and type of pollutants, duration of exposure, level of physical activity and a person’s underlying health.
During exercise or strenuous outdoor work, breathing becomes faster and deeper. This can increase the amount of polluted air reaching the lungs. Exposure may also aggravate asthma, COPD and cardiovascular disease.
For many healthy people, short-term exposure causes temporary irritation. In higher-risk individuals, however, poor air quality may trigger wheezing, breathlessness, chest discomfort or worsening of an existing condition.
Common Haze-Related Symptoms
Haze health effects are not limited to the lungs. Common short-term symptoms may include:
- - Dry, sore or irritated throat
- - Cough or increased phlegm
- - Runny or blocked nose, sneezing or post-nasal drip
- - Itchy, red or watery eyes
- - Headache, dizziness or unusual tiredness
- - Chest tightness or chest discomfort
- - Wheezing or shortness of breath
- - Worsening asthma or other chronic respiratory symptoms
Some symptoms improve after exposure is reduced. Others should not be dismissed as “just haze”, particularly if breathing becomes difficult, chest pain develops or an existing heart or lung condition becomes harder to control.
How Haze Affects the Lungs, Heart and Body
The respiratory system is the main route through which air pollution enters the body. Fine particles can irritate the nose, throat and bronchial tubes, promote inflammation and affect lung function. In people with sensitive airways, exposure may provoke coughing, wheezing and airway narrowing.
Very small particles may also pass from the lungs into the bloodstream. This helps explain why air pollution is associated with respiratory problems as well as cardiovascular disease. The World Health Organization identifies stroke, ischaemic heart disease, COPD, lung cancer and pneumonia among the health outcomes strongly linked with air pollution exposure.
Haze may also irritate the eyes, worsen allergic symptoms and contribute to fatigue or headache. Consider symptoms alongside API readings rather than visibility alone.
Haze Health Risks for Children
Children are among the groups more susceptible to air-pollution-related illness. During unhealthy haze conditions, reduce prolonged or strenuous outdoor play, particularly for children with asthma, recurrent wheezing or other respiratory conditions.
Parents should keep prescribed asthma medicines available and follow the child’s asthma action plan when one has been provided.
Seek medical advice if a child develops persistent wheezing, rapid or laboured breathing, difficulty speaking or feeding because of breathlessness, unusual drowsiness, or symptoms that do not improve after moving indoors.
Risks for Older Adults and People With Chronic Disease
Older adults may face greater risk from air pollution, particularly when they have heart disease, COPD, diabetes or other chronic illnesses. Pregnant women and people with existing heart or lung conditions should also take additional precautions.
People with chronic conditions should continue prescribed medicines unless a doctor advises otherwise, keep rescue medication accessible when applicable, and minimise unnecessary outdoor exposure when the API is elevated.
Avoid smoking and second-hand smoke. Malaysia’s Ministry of Health advises against smoking during haze because tobacco smoke adds further respiratory exposure.
Understanding Malaysia’s Air Pollutant Index
Malaysia uses the Air Pollutant Index to communicate ambient air quality and its potential health implications. The Department of Environment calculates the API from monitored air pollutants and reports conditions from good through to hazardous.
| API Reading | Air Quality Status |
|---|---|
| 0–50 | Good |
| 51–100 | Moderate |
| 101–200 | Unhealthy |
| 201–300 | Very unhealthy |
| 301–500 | Hazardous |
At unhealthy levels, sensitive groups require greater precautions and outdoor activity should be limited. As air quality becomes very unhealthy or hazardous, reduce outdoor exposure further in accordance with current government health advice.
Always check the latest official API reading for your area rather than judging air quality from smell or visibility alone.
How Are Haze-Related Health Problems Diagnosed?
There is usually no single test that confirms a specific “haze illness”. Diagnosis is based on symptoms, exposure history, underlying health conditions and clinical findings.
A doctor may ask when symptoms started, whether they worsen outdoors, and whether you have asthma, COPD, allergies or heart disease. The examination may include listening to the lungs and checking breathing rate, heart rate, blood pressure and oxygen saturation.
Depending on the symptoms, further tests may include peak-flow measurement or spirometry for suspected airway problems, a chest X-ray when pneumonia or another lung condition is suspected, an electrocardiogram for certain chest or cardiac symptoms, or other investigations based on clinical assessment.
The aim is not only to associate symptoms with haze. A healthcare professional may also need to exclude a respiratory infection, asthma exacerbation, cardiovascular problem or another condition requiring specific treatment.
Treatment for Haze-Related Symptoms
Treatment depends on the symptoms and underlying condition rather than haze exposure alone. For mild irritation, the first step is generally to reduce further exposure by moving to a cleaner indoor environment and avoiding strenuous outdoor activity.
Staying adequately hydrated may help with throat dryness. Prescribed inhalers and other long-term medicines should be used as directed. A clinician may recommend treatment for particular symptoms or for an asthma or COPD exacerbation.
Antibiotics do not treat airway irritation caused by haze itself. Do not start antibiotics, oral steroids or increase prescription doses without medical advice unless the change is already included in a clinician-approved action plan.
Recovery varies. Mild eye, nose and throat irritation may improve after exposure is reduced. A significant asthma flare, bronchitis, pneumonia or cardiovascular problem may require longer treatment and medical follow-up.
How to Prevent Haze-Related Health Problems
The most effective prevention strategy is to reduce the amount of polluted air you inhale.
- 1. Check the API before making outdoor plans. Pay particular attention when planning for children, older family members or people with chronic heart or lung disease.
- 2. Reduce strenuous outdoor activity when air quality is unhealthy. Exercise increases breathing rate and may increase the amount of pollutants inhaled.
- 3. Keep indoor air cleaner. Close windows and doors when outdoor air quality is poor. Air-conditioning recirculation mode may reduce outside air entering the space. An appropriately sized high-efficiency particle air purifier may also help when used correctly.
- 4. Use appropriate respiratory protection when necessary. A correctly fitted N95 respirator offers better protection from fine particles than a surgical mask. Respirators may not suit everyone, so people with heart or lung disease and parents considering them for children should follow current medical and official advice.
- 5. Avoid adding indoor pollution. Do not smoke indoors, and minimise other sources of smoke or airborne particles during haze episodes.
- 6. Follow your disease action plan. People with asthma and other chronic respiratory conditions should keep prescribed medicines accessible and know what to do if symptoms worsen.
- 7. Seek medical care early when symptoms escalate. Early assessment is especially important for higher-risk individuals.
When Should You See a Doctor?
Arrange a medical assessment if coughing, wheezing, eye irritation or breathlessness is persistent, worsening or interfering with normal activities. Seek care promptly when haze appears to aggravate asthma, COPD, heart disease or another chronic condition.
Seek emergency assessment for:
- - Severe shortness of breath
- - Chest pain or pressure
- - Bluish lips or skin
- - Confusion or fainting
- - Inability to speak normally because of breathlessness
- - A severe asthma attack that does not respond to prescribed rescue treatment
Do not assume that serious chest or breathing symptoms are caused only by haze.
Which Doctor or Specialist Should You See?
A general practitioner or emergency clinician can assess many acute haze-related symptoms. A respiratory physician may be appropriate for persistent cough, recurrent wheezing, asthma, COPD or abnormal lung-function findings.
Children with significant respiratory symptoms may need assessment by a paediatrician or paediatric respiratory specialist. KPJ’s specialist services include paediatric respiratory expertise within its network. People with concerning cardiovascular symptoms may require assessment by a cardiologist or emergency team.
When searching for a haze-related doctor or specialist, focus on the symptom or underlying condition rather than haze alone.
Choosing a Hospital for Haze-Related Concerns
The appropriate level of care depends on symptom severity, age, medical history and location.
A suitable hospital should be able to assess respiratory and cardiovascular symptoms, provide emergency stabilisation when necessary and arrange specialist follow-up. KPJ Healthcare’s hospital network provides access to specialist care, while individual hospitals may also provide Accident & Emergency services for acute conditions.
If symptoms are severe, go to the nearest appropriate emergency department rather than travelling a long distance to a preferred facility.
Frequently Asked Questions About Haze Health Risks
1. Can haze cause a fever?
Haze itself generally causes irritation rather than fever. Fever may indicate an infection or another medical condition, particularly when accompanied by worsening cough, body aches or marked fatigue. Seek medical advice if the fever persists or you are uncertain about its cause.
2. How long do haze symptoms last?
Mild irritation may improve after exposure is reduced, but recovery time varies. Persistent coughing, wheezing, breathlessness or chest discomfort should be medically assessed rather than simply waiting for the haze to clear.
3. Can a surgical mask protect against haze?
A surgical mask does not provide the same seal or fine-particle filtration as a properly fitted particulate respirator. Malaysia’s Ministry of Health identifies N95 respirators as an option for reducing exposure to fine haze particles when they are appropriate and correctly fitted.
4. Should people with asthma exercise during haze?
When the API is unhealthy, people with asthma should reduce strenuous outdoor activity and follow their asthma action plan. If exercise triggers coughing, wheezing or breathlessness, stop the activity and move to cleaner air. Seek medical care if symptoms are not relieved by prescribed medication.
Protect Your Health During Haze in Malaysia
Haze is more than a visibility problem. Fine airborne particles can irritate the respiratory system, aggravate chronic disease and place vulnerable individuals at greater health risk.
Monitor Malaysia’s API, reduce unnecessary exposure, keep indoor air as clean as possible and take worsening symptoms seriously.
Concerned About Haze-Related Symptoms?
If you or a family member has persistent respiratory symptoms, worsening asthma, chest discomfort or other concerning signs, consult a qualified healthcare professional.
Find a Doctor or SpecialistThis article is intended for general health information and does not replace individual medical advice, diagnosis or treatment.
* https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health












