Types of Asthma
Many asthmatics develop their symptoms in childhood and have asthma triggered by exposure to animals, dust or pollens.
Late onset or non-allergic asthma
Some people develop asthma later in life ,often in their 30s or 40s, without any clear external or allergic triggers. This type of asthma is commoner in women and may be related to sensitivity to aspirin and related drugs.
Exposure to dusts, chemicals or other agents can cause asthma in the workplace.