By law you need to tell the DVLA about any health condition that may affect your ability to drive. Failure to do so could lead to prosecution and invalidate your insurance. Problems that you should consider reporting include tachycardia, syncope and dizziness. It does not always mean that you will be stopped from driving. Follow link for further information, forms and a list of conditions which may affect your driving.
Flying causes dehydration and can worsens symptoms.
Drink more fluid than normal - You can take an empty drinks bottle through security. If you explain that your medical condition requires high fluid intake, they will fill it for you during the flight.
Wear compression stockings.
Elevate your feet where possible.
Avoid staying stationary for too long; get up and walk around when possible.
Take snacks with you and eat regularly to avoid a drop in blood sugar, particularly when travelling at different times.
*Currently no available medical evidence. Based on patient experience and opinion.