Asthma is a common illness of the airways of the lungs. The airways become obstructed in response to stimuli, making it hard to get air in and out of the lungs, causing breathlessness and wheezing. People with asthma have sensitive airways which may be irritated by a trigger in the environment (such as pollen), by an illness, or by an emotion (such as anxiety). The irritation causes the airways to swell up and the muscles surrounding the airways to tighten so that it becomes difficult to breathe.

Asthma can be quite different between different people – the severity and the symptoms can vary. In New Zealand one in seven children and one in eight adults need to take medicine for asthma.

Asthma is common in children, but about a third will grow out of it. Many children who wheeze will not go on to develop asthma at all. Asthma can persist for some people; this may require the use of inhalers to prevent the symptoms for an indefinite period.

Poorly insulated homes that are damp and cold can trigger your asthma symptoms. Make sure your home is well insulated, quality, well-installed ceiling and underfloor insulation is the top priority for a warmer, healthier home. It's important to get air flow through your home, ensure windows are opened during the day and curtains are closed in the evening.

Keeping your home well aired can help reduce exposure to some common indoor triggers. Regularly airing out your home is beneficial to your health, even in winter, to minimise the impact that any fumes from fires, cookers, cleaning products, and sprays have on your asthma as these are cleared away more quickly. It also helps prevent problems like damp and mould.

When choosing which heating is best for your home if you suffer from asthma, try to avoid open fires, wood burning heaters and fires, portable or bayonet fitting unflued gas, kerosene or LPG canisters and heaters as they release pollutants and water vapour into your home. This will cause asthma symptoms to worsen as tiny particles that can get into the airways. Breathing them in can make your airways inflamed, bringing on asthma symptoms. Central heating and heat pumps are better options for people with asthma.