Why Do I Feel Sick After Traveling?

We’ve all been there: your long-awaited vacation is over, but instead of feeling refreshed, you’re stuck wondering why you’re sick after travel again. Whether you’re dealing with a scratchy throat, fatigue, or general unease, there are several key factors that may have contributed to your post-travel sickness:

1. A weakened immune system from stress and poor sleep
2. Low humidity in airplane cabins that dries out protective membranes
3. Extended exposure to recycled air and airborne germs
4. Close contact with many people in confined spaces
5. Exposure to new environments and allergens
6. Disruption of normal eating and sleeping patterns

If you have returned home from a vacation with more than just a souvenir, don’t hesitate to visit a Complete Care ER location. While post-travel illness is common, it’s important to have any worrisome symptoms evaluated by our healthcare providers, who can properly assess your condition and provide appropriate treatment.

Learn more: How to keep from getting sick while traveling

1. A weakened immune system from stress and poor sleep

When you travel, your immune system faces a double challenge from stress and disrupted sleep. The planning, packing, and navigating unfamiliar places create elevated levels of stress hormones like cortisol, which can suppress your immune response. At the same time, crossing time zones throws off your body’s natural circadian rhythm — the internal clock that regulates sleep-wake cycles and immune function.

During normal sleep, your body produces crucial immune cells that help fight off infections. However, travel disrupts this process through early morning flights, late-night arrivals, and the general discomfort of sleeping in new places. Combined with irregular meals and less physical activity, these factors create the perfect storm for a temporarily weakened immune system, making you more susceptible to catching whatever viral or bacterial cold you encounter along the way.

2. Low humidity in airplane cabins that dries out protective membranes

The air inside airplane cabins is notoriously dry, with humidity levels often dropping below 20%, significantly lower than what your body is used to. Many passengers report feeling sick after flying specifically, and this is one of the big reasons why. For comparison, most homes maintain humidity levels between 30-60%. This extremely dry environment affects one of your body’s most important defense mechanisms: the mucous membranes that line your nose, throat, and airways.

These membranes normally act as a protective barrier, trapping and filtering out viruses, 

bacteria, and other harmful particles before they can cause infection. However, when exposed to such low humidity, these membranes become dried out and less effective. 

This explains why a sore throat after flying is such a common complaint. Think of it like a piece of tape losing its stickiness — when your mucous membranes dry out, they’re less able to catch and eliminate potential threats, leaving you more vulnerable to getting sick during and after your flight.

3. Extended exposure to recycled air and airborne germs

If you’re someone who says, “I always get sick after traveling by plane,” in addition to the very low humidity, the culprit might be the aircraft’s air circulation system. While modern airplane air filtration systems are sophisticated, using hospital-grade HEPA filters that capture 99.9% of airborne particles, you’re still sharing recycled air with hundreds of other passengers in an enclosed space for hours. This means you’re repeatedly exposed to whatever germs your fellow travelers might be carrying.

The combination of recycled air and close quarters creates an environment where viruses and bacteria can more easily spread. Extended exposure to this petri-dish-like environment can result in a variety of symptoms, from common respiratory issues to more unusual reactions like a skin rash with cold symptoms. This extended exposure to recycled air, often for several hours at a time, gives airborne pathogens more opportunities to overcome your body’s natural defenses, especially when combined with other travel-related stressors.

4. Close contact with many people in confined spaces

Ever noticed how crowded airports and planes have become? Getting sick after traveling is often linked to this unavoidable close contact with others. From packed security lines and crowded gate areas to shoulder-to-shoulder seating on planes, travel involves prolonged exposure to dozens or even hundreds of people in confined spaces.

This close proximity creates an ideal environment for the spread of infectious illnesses. When someone coughs, sneezes, or even talks nearby, respiratory droplets can easily travel in these confined spaces. Think of it like being in an elevator for several hours, except the elevator is filled with people from different cities, countries, and environments, each carrying their own unique set of germs. This extensive exposure significantly increases your chances of catching something during your journey.

5. Exposure to new environments and allergens

When you travel, your body suddenly encounters an entirely new set of environmental factors it isn’t used to. Different regions have their own unique blend of pollens, dust, molds, and air quality levels. Your immune system, which has adapted to your home environment, suddenly needs to work overtime to process and respond to these unfamiliar allergens and irritants. This is particularly true when traveling internationally, where you might be exposed to diseases like measles* that are more common in certain regions than others.

Your body may also react to different types of plants, varying pollution levels, or even changes in air quality between urban and rural areas.

*Continue reading: How long does measles last?

6. Disruption to normal eating and sleeping patterns

Travel often throws your body’s carefully balanced routines into chaos. When you cross time zones or keep irregular hours, you’re not just feeling tired — you’re disrupting your body’s internal clock that regulates everything from digestion to immune function. 

Some travelers even report left side pain and other digestive issues when their eating schedule is thrown off course, especially when combining unusual meal times with unfamiliar foods or different water sources. Add in jet lag that disrupts your normal sleep cycles, and you’ve got a recipe for feeling off-balance. These disruptions can weaken your body’s natural defenses and make you more susceptible to feeling unwell during or after your journey.

Is it normal to get sick after travel?

“Why do I get sick after traveling?” is one of the most common questions we hear from patients. The simple answer is that it’s completely normal to feel under the weather after a trip. Some people even experience what’s known as “leisure sickness” — a phenomenon where those who do not take time to relax regularly often fall ill on vacations or weekends.

While getting sick isn’t inevitable, it’s a common enough occurrence that many frequent travelers come to expect some form of post-trip illness. The good news is that most travel-related illnesses are minor and temporary if you’re able to get plenty of rest, drink plenty of fluids, and take it easy until you feel better.

However, if you notice these symptoms are either persisting or worsening, it would be a good idea to seek medical attention.

Experiencing flu-like symptoms after traveling? Complete Care is here to help.

Feeling sick after travel ​​can be a frustrating feeling, but try to remember that it’s not unusual to feel this way. Travel, even when done in the most cautious manner, can still be exhausting on the body.

If you do find yourself in need of medical attention, the staff at Complete Care is here to help you feel better in no time. With low wait times and hospital-quality care, those nasty symptoms after traveling will be a thing of the past.

With many ER locations all across Texas (Austin, Corpus Christi, Dallas/Fort Worth, East Texas, Lubbock, and San Antonio) and in Colorado Springs all open 24/7 for you and your family, we are here in your time of need.

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