The Science Behind Feeling Sick on Holiday

Leisure sickness is a phenomenon where people often fall ill during holidays or weekends, just when they’re supposed to be relaxing and recharging

CREDIT: This is an edited version of an article that originally appeared in Self

There’s never a great time to get sick, but certain moments feel especially cruel – like when you’re finally about to enjoy some well-earned time off. Few things sting more than spending the first days of a holiday stuck on the couch with a head cold or feeling completely drained. Yet oddly enough, that’s often exactly when illness shows up, as if your body has picked the worst possible moment to rebel.

Back in 2002, Dutch psychologist Ad Vingerhoets, PhD, gave this phenomenon a name: leisure sickness. It describes the peculiar tendency to feel unwell during weekends or longer breaks. Symptoms can range from full-blown colds and flu to muscle aches, headaches, or sheer fatigue. It seems counterintuitive – rest and relaxation making you sick – until you consider what’s going on beforehand.

Before a holiday, many people are racing to meet deadlines, ploughing through endless tasks, and dreading the email mountain that will await their return. Stress hormones like adrenaline and cortisol kick in to help you power through, revving up your pulse, breath and immune defences. But once the pressure lifts, that “fight-or-flight” switch turns off – and your body can crash. Add in pre-travel stress, anticipation, and a change in routine, and suddenly your immune system feels like it’s running on empty just as you hit the beach.

Make an everyday effort to manage stress

Long-term stress chips away at immunity, so experts suggest weaving stress-busting habits into daily life. Simple practices – mindfulness, short breaks, even deep breathing – help build resilience, making it easier to stay well when the pre-vacation chaos kicks in.

Double down on basic health hygiene

Supporting your immune system doesn’t have to be complicated. A balanced diet, regular movement and plenty of sleep go a long way in keeping you feeling steady. While these habits are valuable year-round, they’re especially helpful in the frantic days before heading away.

Ease yourself into vacation mode

Shifting gently from work mode to holiday mode helps your body adjust. Try keeping to roughly your usual sleep and wake times for the first few days of a break and stick with some light movement – even just long walks – to keep your energy steady.

Leisure sickness is real (even if it isn’t a medically recognised condition!), but with a bit of planning, you can avoid that “holiday hangover” feeling.  After all, the last thing you want is to need a holiday just to recover from your holiday!