The phenomenon known as 'leisure sickness' or 'let-down effect' describes people getting sick as they begin to relax during time off work or holidays. While anecdotally common, scientific evidence is limited and studies have faced design challenges. Early research suggested symptoms like headaches, tiredness, and colds occur more frequently during holidays. A separate study indicated stress reduction might trigger migraines for some individuals. Further research is needed to fully understand and validate this effect.