As they are some of the most common triggers, pollen and spores can affect many people with asthma and allergic rhinitis.

The amount of pollen and spores in the air changes with both the time of year and the time of day.

As the seasons change, different plants, moulds and fungi release their pollen and spores. Most plants, for example, release pollen in the morning when the air is cooler.

As the air heats and rises during the day the pollen is carried up where it can be blown over a wider area.

As the air cools in the late afternoon and evening, pollen falls back towards ground. Pollen and spored can be carried very far from their source and so can affect people in towns and cities and those in the countryside

Although difficult to avoid pollens and spores altogether, several steps can be taken, depending on what situation you are in, outdoors or indoors.