Understand and manage asthma triggers

Identify what might be causing those asthma symptoms and learn how to deal with them to take control of asthma.

What is an asthma trigger?

At its simplest, an asthma trigger is anything that makes us get asthma symptoms or an asthma attack. Different people are affected by different asthma triggers. These can include:

You do not have to entirely avoid all of these asthma triggers. Exercise, for example, is not something we should have to give up. And we certainly cannot control or avoid the weather.

Talk to your doctor to identify the triggers that affect you and what can be done. Some of the tips outlined here might help.

If you are very sensitive to asthma triggers, you might want to ask your doctor about long-term control medicine for your asthma.

Some asthma triggers and basic ways to manage them


An allergen is a normally harmless substance that triggers the immune system to overreact in people with allergies. This response can cause allergy symptoms such as sniffling, sneezing, itchiness and watery eyes. Allergens can also cause asthma symptoms.


Asthma symptoms can be caused by the dried droppings and remains of cockroaches.

  • Keep food and garbage in closed containers; never leave food out
  • Use bait or traps to eliminate cockroaches
  • If you use a spray to any cockroaches, stay out of the room until the odour goes away

Dust mites

Dust mites and their droppings can cause asthma symptoms if left unchecked.

  • Clean any carpets regularly or replace them with wood or tile flooring
  • Cover your bedding (mattress, pillows, comforter) when not in use
  • Wash your bed sheets every week in hot water
  • Regularly open windows to reduce indoor humidity

Indoor mould

Mould can grow in damp or humid areas of our homes. When we breathe in their spores, it might trigger an asthma attack.

  • Use a vinegar solution to clean mould off walls
  • Avoid using carpeting and other flooring that retains moisture
  • Reduce humidity in your home, to below 60% if possible
  • Fix any leaky taps or pipes to eliminate mould forming

Pet-related allergens

The proteins in a pet’s dander (the dead skin and fur or feathers shed by the pet), saliva and urine might trigger asthma symptoms. Pets’ fur or feathers might also collect other allergens.

  • You may not need to rehome the pet – see an allergist or immunologist to see whether a treatment plan is possible
  • At the very least, keep the pet away from the bedroom

Pollen and outdoor mould

Seasonal allergies caused by pollen or outdoor mould are not that common in Singapore, but if you’re affected:

  • Try to keep windows closed and use air-conditioning when indoors
  • If possible, stay indoors during the late morning and in the afternoon; pollen and mould-spore counts are highest during those times


An irritant is something that irritates the airways, leading to asthma symptoms. For example:

Strong odours, sprays, smoke

Chemicals in the air might trigger your asthma.

  • Try to avoid or minimise your exposure to sprays or strong odours like perfume, talcum powder, hair spray and paint
  • Don’t stay too close to wood or charcoal smoke, or at least not for too long

Cigarette and other tobacco smoke

Any form of tobacco smoke is never good for asthma and your lungs.

  • Quit smoking if you are a smoker
  • Ask people not to smoke around you

Food sensitivities

If you get asthma symptoms after eating or drinking, it may be because you are sensitive to something called sulphites.


These occur naturally when making some types of food, or may be added to food as a preservative.

  • Monitor what you had to eat or drink before an attack and see if it happens again
  • Examples of foods with sulphites are beer, wine, shrimp, dried fruit and processed potatoes


It was once thought that we should not or could not exercise if we had asthma. That is no longer the case. Today, doctors recommend that most people, including those with asthma, get at least 30 minutes of moderate exercise most days of the week. It’s just that with asthma, a little more care should be taken.

Asthma and exercising

Asthma symptoms might be triggered when we are exercising or about 5 to 20 minutes after, and they usually do away in about 20 to 30 minutes.

  • Plan and adjust exercise carefully, under your doctor’s supervision
  • If you have been prescribed medicine for asthma symptoms that may be triggered by exercise, always take the medicine as instructed
  • Warm up by stretching or walking for about 10 minutes before you exercise
  • Doing cool-down exercises can help, but speak to your doctor about that and ask about what to do if you get asthma symptoms during a cool-down

Colds and respiratory infections

Colds or other respiratory infections might trigger asthma symptoms for some people.

Asthma when you’re not well

If your asthma worsens when you have a cold or other illness:

  • Talk to your doctor about adding instructions to your Asthma Action Plan for those times you’re not well
  • Ask your doctor about getting a regular flu shot
  • Get plenty of rest and fluids
  • Avoid contact with others who have a cold or flu


Our tropical climate means we do not get the cold air that can trigger asthma. However, we sometimes get affected by haze in Singapore as a result of forest fires in the region.

Haze and asthma in Singapore

The dust, smoke, chemicals and other dry particles in the haze might aggravate asthma symptoms or cause more severe asthma attacks.

  • Ask your doctor what to do about your asthma when there is haze
  • Take note of any haze-related health advisories issued and follow the instructions

Cold weather

If you are sensitive to cold temperatures:

  • Cover your nose and mouth with a scarf when outdoors on cold or windy days or when you travel to cooler climates
  • See our asthma management travel tips below for more advice


For some of us, stress might trigger asthma symptoms. Though we cannot avoid stress entirely, we can use these tips to manage it.

Recognise your stress triggers

If you are unsure about what is triggering your stress and asthma, try keeping a record of stressful events for a couple of weeks. Review them to identify the triggers.

Me time

Take time out for yourself and do the activities you enjoy. Taking a step back from things can help you to relax.

Eat a healthy, balanced diet, with plenty of fruit and vegetables

Too much sugary and processed foods can cause your blood sugar levels to increase and decrease quickly, which makes your stress symptoms worse.

Do some exercise

Something as simple as a walk in the park can do a lot to help you reduce stress and feel better.

Talk to friends or family

Do not be afraid to open up to your close friends or family members about how you are feeling. Talking to others may help you feel better.

Organise what you have to do

Write down the things you need to do and prioritise them. It’ll help clear your mind and give you back some control over your time.

More tips to manage asthma triggers

Your asthma medications are key to minimising how asthma triggers affect you, so be sure you take them exactly as your doctor instructed.

Remember to take your medication as prescribed

Some asthma medication needs to be taken daily, even if you are not experiencing any symptoms. To help you take your medicine regularly and not forget:

  • Make taking your medicine part of your daily routine
  • Set a regular alert on your phone or computer

Make sure you always have enough medication

It is very important that you do not miss a dose of your asthma medication. In fact, it can even be dangerous if you are caught in a situation without medication.

  • Refill your prescription early – make a note on your calendar to get more medicine a week before it is due to run out
  • Check that you have enough quick-relief medicine and that it’s not expired
  • If your medicine has a dose counter, get more medicine before it reaches zero doses

Do not stop medication unless the doctor advises you to do so

If you are prescribed long-term control medicine and you find that you have not had any asthma symptoms for a while, that does not mean you can stop taking the medicine. The symptoms might return if you do. Speak with your doctor first.

Sometimes, the work environment or conditions might be aggravating your asthma.

Watch out for asthma triggers

If work regularly exposes you to asthma triggers such as dust, mould, chemicals, animals, smoke or fumes, follow these steps.

  • Your doctor can help you determine what substances may be causing your symptoms – talk to him or her for advice and be sure to list out all the possible triggers you encounter at work
  • Once you have identified one or more possible triggers, ask your employer about moving you to a different location or reassigning you to a different task to minimise your exposure

Take note of the air quality

If the air quality or ventilation in your office is poor, it might affect your asthma.

  • Talk to your employer if the office environment is causing asthma symptoms

Reduce stress

If stress at work triggers your asthma:

  • Try to reduce on-the-job stress by managing your time effectively so you are not overworked
  • Practice relaxation techniques
  • Use some of the ways listed earlier on this page to help relieve stress

Asthma does not have to stop you from seeing the world and enjoying a nice holiday. Just take a little more time to plan so that you’re fully prepared when overseas.

See your doctor before you travel

Ask your doctor for advice when you’re planning a trip. Cold climates or high altitudes (for example, if you’re going skiing) might trigger asthma. So might activities like scuba diving. If your asthma is more severe, ask your doctor whether air travel is safe for you, as well as what precautions to take.

Bring these necessary documents

Bring a list of all of your medications, extra prescriptions for additional medication, a copy of your Asthma Action Plan, and your insurance cards.

Carry your quick-relief inhaler

You should always have your quick-relief inhaler on hand for any sudden asthma symptoms. This is particularly important when far from home.

Fill your prescriptions

Make sure you bring enough medication to last through your whole trip. Consider bringing extra medicine and remember to bring along your prescription as you may need to show this at the customs checkpoint.

Do not pack medication in your checked bags

Keep your medication in a bag you will carry with you, just in case the checked luggage gets delayed or lost.

Make sure you can power your nebuliser

If you bring along a nebuliser that requires power, make sure you have the right adapter to use it in different countries. If the nebulizer is battery-powered, make sure the battery is charged.

Asthma Toolbox

Asthma Control Test

This quick 5-question test indicates your level of asthma control.  

Asthma Action Plan

This is an important guide your doctor can prepare for you to help you stay ahead of asthma at all times.


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SG/AST/0005/15a Certified 26/04/16.