These can be signs of a serious allergic reaction and may need immediate treatment in hospital. What to do if you have anaphylaxis use your adrenaline auto-injector if you think you may have anaphylaxis, even if your symptoms are mild you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air) Use an adrenaline auto-injector (such as an EpiPen) if you have one – instructions are included on the side of the injector.

You may also be referred to an allergy specialist for tests. Things you can do to help prevent anaphylaxisverifyErrors }}{{ message }}{{ /verifyErrors }}{{

Lie down – you can raise your legs, and if you're struggling to breathe, raise your shoulders or sit up slowly (if you're pregnant, lie on your left side). Before you leave hospital, you'll be given 2 adrenaline auto-injectors to keep in case you have another anaphylactic reaction.

An adrenaline auto-injector is a special device for injecting adrenaline yourself. You'll be told how and when to use it.