Allergy-sufferers are at risk of “life-threatening” asthma attacks triggered by birch pollen, experts warned.

Severe asthma attacks can block the airways completely, resulting in brain injury or death.

More than three million

Brits with asthma are allergic to pollen — and they have been reminded to keep their inhalers close in case of emergency.

Sonia Munde, head of services at Asthma UK, told The Sun Online: “A deadly pollen bomb is due to hit this week, putting people with asthma at risk of a potentially life-threatening asthma attack.