Few people like air travel for long periods, but you can do a few things to minimize discomfort.:

Travel sick: Take-off, turbulence and landing promote queasiness. Choose seats over the wings (most stable) and focus on a still object until the feeling passes.

Exhausted: To minimize fatigue, once on board, switch to your destination's time zone and try to sleep or rest according to that.

Uncomfortable: Move around regularly and do stretching exercises in your seat. The risk of deep vein thrombosis (DVT), although small, is higher for those with pre-existing conditions, so seek medical advice before traveling.

Hungry: Inactivity makes it harder to digest food, so avoid excessive snacking. Humidity levels in the cabin are low, so drink plenty of water-tea, coffee and alcohol will dehydrate you.