Some people know this all too well: The vacation finally arrives, you begin to unwind, and then a sore throat, weakness, fatigue, or a cold appear. This phenomenon, sometimes publicly referred to as "vacation sickness," is not an official medical diagnosis, but it is well recognized in medical and behavioral discourse. In most cases, it involves a combination of a sudden drop in tension, changes in routine, and exposure to existing infections that the body was coping with during times of high workload.
Why does this happen specifically at the beginning of a vacation? During periods of stress, the body operates in a state of continuous alertness. Stress hormones such as cortisol and adrenaline affect not only the feeling of alertness, but also the way the federal immune system functions.
When stress drops all at once, such as at the beginning of a vacation, the body transitions into a state of relaxation. For some people, it is precisely at this stage that symptoms appear which were not felt before, or a mild illness that was "in the background" becomes more apparent.
In addition, a sharp change in routine such as different sleep hours, flights, a different diet, and exposure to enclosed spaces can burden the body during the transition period.
What do we know today about the phenomenon?
The phenomenon was first described as early as the beginning of the 2000s under the name "leisure sickness" as a phenomenon in which people experience symptoms such as fatigue, headaches, and cold symptoms specifically on weekends or vacations.
Concurrently, public health studies show that sharp changes in routine, a decline in sleep quality, and exposure to a new environment (such as on flights and vacations) can increase the risk of a poor general feeling and even symptoms resembling a mild infection. Alongside this, recent observational studies also show that the phenomenon exists in reports from travelers and people on vacation, but it is not defined as a clear medical illness, rather as a multi-factorial phenomenon.
It is not always a "new illness"
It is important to understand that in many cases, this is not an illness that appears because of the vacation itself. Sometimes it is an infection that had already begun beforehand, but during a heavy workload at work, the body "pushes forward," and only when there is rest does it allow the symptoms to manifest fully. In other words, the body does not always get sick because one is resting, but rather, sometimes you simply begin to feel what was already there.
Studies show that the phenomenon is less related to a decline in immunity and more to a psychological difficulty in transitioning from a work state to rest. People with a tendency toward high achievement and difficulty unwinding, who live under a high workload, are at a higher risk. In addition, changes in routine, travel-related stress, changes in sleep, and exposure to new environments (such as airplanes and hotels) can increase the risk of new infections or a worsening of existing symptoms. It is important to clarify: Acute stress actually strengthens the immune system in the short term, and therefore the drop in stress itself is not the cause of the weakness.
How can the phenomenon be reduced?
There is no way to completely prevent the appearance of such symptoms, but it is possible to reduce the probability:
• A gradual transition to a vacation routine instead of a sharp change
• Ensuring sufficient sleep before and during the vacation
• Sufficient hydration and avoiding overload in the first days
• Allowing acclimatization time for the body, especially after flights and changes in climate and altitude
It is important to remember that although the phenomenon is well described in the literature, it is not common – studies show that only about 3% of the population experience it on a regular basis. Most people enjoy a vacation as an opportunity for stress reduction, with positive health effects.
Dr. Lee Erez, Specialist in Family Medicine, Maccabi Healthcare Services, Northern District