Why do I always get sick on holiday?

After a relaxing vacation, you’d think your body would be so rejuvenated that your immune system would be in tip-top shape. But it’s like clockwork: The second your plane lands back home, sniffles or body aches surface out of nowhere. How on earth can a week of sipping mojitos on the beach cause you to get sick when that’s the opposite of the point?Whether you spend most of your vacation napping in a lavish hotel bed or walking miles through the streets of a new city, it’s certainly a change of pace from your life back home. That’s a lot for your system to adjust to, only for those changes to come to a grinding halt when you arrive back home again and jump right back into your usual routine.