Why do I always get sick on holiday?

Exhaustion (Again)

Flights get canceled. Trains get delayed. You opted for dead-of-the-night travel plans to save some cash at the tail end of your trip. All of these things make getting back home and into your typical routine extra difficult, and you end up feeling pretty wiped out as you finish your vacation rather than truly restored and ready to go. So don’t be surprised if this final trek does you in while your immune system is already unhappy.