(I'm age 14.)

Hi, for the past 9 months I've been having these attacks where I suddenly have palpitations, breathing difficulties (feel like I'm holding my breathe because not enough air is going into my body), numbness in fingers, hands, feet, face etc., bloodshot eyes, high blood pressure, fast but regular heartbeat, go white and start dripping with sweat.

I've had 3 ambulances and one from school and been through GPs, cardiologists and allergy consultants, yet noone seems to be able to diagnose me.

When it happens I'm not stressed or panicking, and it's very random - I could be mid-sentence and it comes on suddenly, and when it goes, it goes suddenly.

I was rushed into hospital when i was about 18months as i went blue and stopped breathing, have been seen by doctors for achey legs and have had mild asthma since I was 9. My reliever inhaler does not seem to help me.

I've been tested for thyroid but it's not that, and I have a healthy heart. Any ideas what it could be?