There are certain things and factors which bring on asthma symptoms. List of some of those are given below:-

A. Allergens

1. Dust mites: - These are the most common indoor allergens which are associated with asthma. Mites are microscopic insects. Mites and their faeces in house dust constitute the main source of dust-derived allergens. Like animals, human beings also shed dander’s (skin flakes), which are food of dust mites. Mites are usually found in bed sheets, beds, pillows, carpets, mattresses, furniture’s etc. Mite sensitive patients develop sneezing and wheezing mainly in the morning.

2. Cockroaches: - Allergy to cockroaches is found in many persons.

3. Pet animals: - Pet animals like dogs and cats can cause asthma in people who are sensitive when pets go outside then pollen, fungus spores get stuck to their furs which are carried by them when they return back and enter inside the house. Pet shed saliva fur and dander all over the house. The sticky saliva holds together the fur and the dander.

Pollen, fungus spores, fur, dander all can trigger off symptoms of asthma. Even a slight exposure to dander can cause narrowing of the airways of peoples who are sensitive to dander.

4. Fungus: - In some persons symptoms of asthma may occur more frequently in some particular season. It means those persons are sensitive to fungi and pollen. Through the windows or other openings of the house fungus spores can enter inside the house along with the wind and settle on house hold goods like mattresses, bed, cushions, furniture etc. In damp, dark and poor ventilated places fungi can grow. In basement, within systems used for cooling and humidification fungal growth can be seen.

5. Pollen grains: - Pollens from grasses, weeds and trees are common pollen allergens associated with asthma.

6. Moulds: - Yeast products including cakes, mushrooms, airborne spores etc.

7. Food: - Those babies who have food allergies have chances of asthma later in life. Milk, ice-cream and other dairy products are likely to cause coughing, wheezing, etc. Some other foods which are associated with asthma are wheat, eggs, oranges, grapes, nuts, bananas, mushrooms, processed foods etc.

8. Chemicals in food (food additives): - There are various types of food additives like food colors, chemicals added to foods for artificial flavors, sweeteners, preservatives etc. Some of these may cause allergic reaction.

Chemicals like tartrazine, monosodium glutamate, benzoic acid, sulphites etc. are food additives which can trigger asthma.

9. Medicines: - Aspirin and non-steroidal anti inflammatory medicines can trigger asthma. Beta-blockers may also trigger asthma.

B. Irritants

1. Pollution in air: - Presence of oxides of nitrogen, sulpher dioxide, S.P.M., carbon monoxide, carbon dioxide etc. in air can trigger asthma and can enhance allergic responses.
S.P.M.: - Suspended particulate matter is a mixture of minute solid particles and liquid droplets which generally comes from ventricle emission, tyre fragmentation plant, tobacco smoke, road dust, pollen grains etc.

When we breathe in, fine particles go inside and stick to the lungs and trigger an allergic reaction. This reaction can lead to asthma.

Carbon monoxide is another pollutant which is dangerous. It generally comes from fossil fuel smoke, vehicle emissions etc. It binds to the haemoglobin of blood, and reduces its oxygen carrying capacity. Oxygen delivery to the tissues is obstructed by carbon monoxide which leads to respiratory disease.

2. Smoking: - Tobacco smoking is dangerous for health. Smoking causes serious lung disease, cancer and heart diseases. Like active smoking passive smoking has also adverse effects on health.

Nicotine levels of babies born to mothers, who are smokers, are as high as those in adult smokers and those babies are likely to develop respiratory diseases including asthma in future.
3. Changes in weather condition: - Changes in atmospheric temperature and pressure are associated with asthma. When the humidity is high in atmosphere, when there is rain or thunderstorm, tightness in chest and excessive secretion of mucus can take place. Tightening of airways in dry and cold air may also happen to some people. Frequent or severe symptoms of asthma can be seen in some people in summer also.

4. Respiratory infection: - Respiratory infection may be caused either by bacteria (known as bacterial infection) or by virus (known as viral infection). Common victims of viral infection are infants and young children. Viral respiratory infection like RSV bronchiolitis in early life can lead to development of asthma in future.

5. Chemicals in house hold goods:- Processed food, plastics, plywood, glue, foam, cosmetics, shampoo, hair sprays, room fresheners, deodorants, etc can trigger symptoms of asthma.

Author: S.N.Bhattacharya