Risk factors

A number of factors are thought to increase your chances of developing asthma. They include:

• Having a blood relative with asthma, such as a parent or sibling
• Having another allergic condition, such as atopic dermatitis — which causes red, itchy skin — or hay fever — which causes a runny nose, congestion and itchy eyes
• Being overweight
• Being a smoker
• Exposure to secondhand smoke
• Exposure to exhaust fumes or other types of pollution
• Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing