I have looked everywhere I can think of and have no information about the association between flying and having a heavier period. So being a quasi-scientist I was trying to figure out if the pressure changes on the plane could be a factor. Pressure on a plane in flight is lower than pressure at sea level but no different really than pressures in locations like Denver where women’s periods are the same as anyone else’s. The only other factor could be the relative stress of flying vs living your normal life on firm ground. No clear answer but it sounds like you know your body and when you are flying, be super prepared for more flow.

I used to travel for work and I spent a lot of time on a plane. I learned how to pack everything I needed for one week into one small suitcase, I was a whiz at navigating airports, and other than Washington DC (where I once got miserably lost) I could navigate my way through any town. I don't remember my period ever being an issue on the plane. But then, my periods are pretty heavy anyway. I do know that flights can mess with your sleep and cabin pressure certainly can affect your ears. I just can't say whether it has any real effect on your period. So I would just recommend being prepared — maybe wear a thin pad even if you haven't started your period and bring some extra pads or tampons in your purse.

I can’t say exactly what is causing this. It could be the pressure, or it could be the stress caused by flying. Those are both shots in the dark. I’d assume that the effect flying has on your body is the reason for this. It’s similar to our immune systems basically shutting down the minute we get onto a plane. We walk onto the plane fine, and we walk off with a cold, flu and whatever else you can catch on a plane. It’s also similar to how stress affects our periods – it can lighten up our flows, or sometimes, maybe, make them heavier.