Emergency health alert: NSW asthma sufferers warned ahead of potentially deadly thunderstorms.

Residents of New South Wales who suffer from asthma and severe hayfever are being warned ahead of pollen-heavy thunderstorms due to sweep the state this week.

The National Asthma Council Australia has issued an alert urging people who suffer from “wheezing and sneezing” to take extra care and enact preventative measures to control their symptoms.

The warning comes after eight Victorians died as a result of ‘thunderstorm asthma‘ last week.

The phenomenon occurs when pollen particles in the air absorb the extra moisture brought by a storm front, causing them to swell and burst. The tiny pieces are then swept by wind to ground level, where they are easily inhaled into the lungs.

READ MORE: What is thunderstorm asthma?

The council’s chair, Dr Jonathan Burdon AM, said it’s a combination that could prove deadly.

“As we have seen with the recent events in Melbourne any serious asthma attack can be life-threatening and have tragic consequences. Act quickly if you start to have symptoms such as shortness of breath or wheezing,” he said in a statement.

“The best way to treat thunderstorm asthma is to avoid it happening by making sure your asthma is under control and following your written asthma action plan.”

Sufferers are advised to carry their puffer with them at all times, take preventative medication (if prescribed), recognise the worsening signs of their condition and stay indoors if necessary.

If your asthma symptoms are rapidly worsening, call 000.

For more information, please visit the National Asthma Council Australia website.