The phenomenon of falling ill during leisure time, known as 'leisure sickness' or the 'let-down effect,' is discussed. While anecdotally common, scientific evidence is limited and studies are often poorly designed. Early research suggested a small percentage of people experience symptoms like headaches, colds, and nausea during weekends or holidays, particularly in the first week of vacation. Some studies indicate stress reduction, rather than ongoing stress, might trigger symptoms like migraines.