What are the causes of asthma? How can it be prevented?

The causes of asthma are:

1. Can be passed on from parents to their children
2. Certain respiratory infections
3. Contact with air-borne allergens such as tobacco smoke, pollen grains, chemicals, dust, mites or some food substances.
4. Cold and cough

Following are the ways to prevent it:

1. A person suffering from asthma should know about the allergens causing asthma.
2. Medicines should be taken after consultation with a doctor.
3. Hygienic and healthy lifestyle should be maintained.
4. Regular checkups for asthma should be done.