Asthma is a condition that affects the airways, the small tubes that carry the air in and out of the lungs. People with asthma have airways that are extra sensitive and react to substances (also known as “triggers”) which irritate them.

Symptoms of asthma include:

• difficulty breathing
• wheezing
• coughing
• chest tightness

Common triggers include:

• colds or flu
• cigarette smoke
• exercise
• allergic responses to pollen, furry or feathery animals or house dust mites

Everyone’s asthma manifests itself differently and can be brought on by different triggers. Your asthma may be brought on by a variety of triggers.

Allergies that affect the upper respiratory system cause inflammation in the nose – a condition called ‘allergic rhinitis’.

The symptoms of allergic rhinitis include:

• sneezing
• itchy and runny nose
• red and watery eyes
• a feeling of congestion that can lead to a headache.

Allergic reactions are caused by substances in the environment called allergens – some examples of the most common allergens are detailed here. For example, seasonal allergies, commonly referred to as 'hay fever', are common and caused by a reaction to pollen from grasses, trees and some other plants, or spores released at certain times of the year. Most cases of seasonal allergies are seasonal, but some people experience symptoms year-round. Other allergies may be triggered by a variety of allergens such as house dust mites, furry or feathery pets or air pollution.