“It may be related to how we are wired,” she says. Mal de debarquement syndrome is quite uncommon, but its effects can reach beyond those returning from cruise ships. Those who take long trips in airplanes, trains and cars may also notice the persistent sensation of motion afterwards.

Getting sick after a cruise, often dubbed "Post-Cruise Crud," is usually caused by the unique environment of a ship, which acts as a "social amplifier" for viruses. With thousands of people from different geographic regions living in close proximity and sharing high-touch surfaces (like buffet tongs, elevator buttons, and stair railings), respiratory and gastrointestinal infections can spread rapidly. Even if the ship is spotlessly clean, "herd immunity" issues arise when passengers bring different strains of the common cold or flu on board. Furthermore, the physical stress of travel—including jet lag, changes in diet, increased alcohol consumption, and lack of sleep—can temporarily weaken your immune system. Many travelers also mistake mal de débarquement (the "sea legs" rocking sensation that can last for days after returning to land) for a physical illness, as it often causes dizziness and nausea. To prevent 2026 post-cruise sickness, prioritize frequent handwashing with soap and water (sanitizer is less effective against norovirus), stay hydrated, and try to get a full 8 hours of sleep to keep your immune defenses strong during the voyage.