Some causes and triggers are common to all people with asthma, and some are more individual, especially allergens (what you are allergic to). The severity of the symptoms or an attack can differ and also be different for different people, and the treatment more or less effective for the individual person.

The following triggers can cause asthma symptoms or start an asthma attack:

• Infections - usually caused by a virus (e.g. colds or flu)
• Allergens – most often from house dust mites, pets or pollen
• Exercise - especially in cold weather
• Emotions - such as excitement, fear or anger
• Irritants - such as air pollution
• Smoking – people with asthma and parents of asthmatic children should avoid smoking
• Changes in the weather - e.g. a cold spell.
• Food additives or allergens – such as tartrazine (an artificial food colouring) or peanuts (in sensitized or allergic people, there can be a systemic allergic reaction).
• Certain medications - some people may be allergic to some drugs, e.g. aspirin

Different triggers can start an asthma attack and there are very big differences between how easily and how severely different people react.

Some triggers (called “inciters”) only cause tightening of the airways (bronchoconstriction) that lasts for just a short time. These triggers might be:

• exercise 
• cigarette smoke 
• changes in air temperature 
• laughing 
• strong smells

Other triggers (called “inducers”) also increase the underlying inflammation of the airways. These triggers might be:

• allergens (such as pets, house dust mites and pollen)
• infections (such as cold, flu, bronchitis/pneumonia)
• certain chemicals

• cigarette smoke 
• diesel exhaust 
• perfume or other strong scents 
• household sprays 
• sulphur dioxide '
• grain or flour dust
• sawdust

Note that some people hardly react at all, whereas others react strongly. This depends on the severity of your asthma and how well it is treated.

Only a few medications can trigger asthma. Check with your doctor or pharmacist before starting with any new medicine. And if you notice any worsening of your asthma, you should see your doctor immediately.

The most common medications that can trigger asthma are:

• Aspirin (acetylsalicylic acid) and certain drugs (known as NSAIDs) used as pain relievers and to treat arthritis and inflammatory conditions
• Beta-blockers (used to treat heart conditions, migraine or anxiety)

Yes, viral respiratory infections – such as the common cold or flu – can trigger asthma, particularly in children. Try to avoid contact with people if you know they have a respiratory infection.

No, asthma is not a psychosomatic condition, it is a chronic inflammatory disease that leads to over-sensitive and easily irritated airways, especially when not treated properly.

But while asthma itself is not psychological, emotional stress is one of the factors that can trigger the symptoms. Financial problems, for example, or not enjoying your work or worrying about your family can be part of what triggers asthma symptoms.

People who have allergic asthma can often easily point out the most common trigger factor(s) for their asthma, for example cats or pollen.

But many people with untreated or under-treated asthma have an underlying airway inflammation that they are hardly aware of. These people will easily react to irritants, allergens and infections. In an environment with more than one trigger it can therefore be difficult to identify the most important one.

If you are provoked by more than one trigger at the same time, the reaction can be stronger than if you are only exposed to one trigger.

For example, an airway infection may cause you to react to stimuli that you normally would not react to.

This is why even triggers like physical exercise, strong smells, plants, chemicals, smoke, weather changes, anxiety, stress and some medications can trigger an asthma attack.

Not all people with asthma feel worse when they are upset or worried. Those who do are probably easily stressed or may cry or hyperventilate (breathe too fast) easily.

Another reason could be that you are not getting proper treatment for the inflammation you have in your airways.