The immune system is our body's alarm system that provides us with an army of cells and antibodies to fight invaders. The immune disorder can lead to chronic illness and pain. We should pay attention to our body's reaction to the external and internal environment and support this delicate and essential system to be in healthy alert mode, instead of being in constant fight & flight mode caused by stress or "dirty" habits, such as forgetting to wash hands after using public bathrooms.

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🔋 What is our immune system?

The Immune System is "a complex network of cells and proteins that defends the body against infection. It keeps a record of every germ (microbe) it has ever defeated so it can recognize and destroy the microbe quickly if it enters the body again. Abnormalities of the immune system can lead to allergic diseases, immunodeficiencies, and autoimmune disorders" (BetterHealth, 2022).

The essential parts of the immune system are antibodies, white blood cells, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These parts are actively fighting infection.

White blood cells

White blood cells are traveling through our body and look out for invaders (microbes), such as bacteria, parasites, viruses, and fungi. Once the white blood cells have found an invader, they launch an immune attack.


As the name might give a hint already, antibodies help the body by recognizing antigens on the surface of the invader (microbe) or in the chemicals of the microbe. Antigens mark the microbe or the toxin as foreign and the antibodies sign the invader is ready to be destroyed by the defense system (immune system). Antibodies and other cells, proteins, and chemicals are involved in the immune attack.

Complement system

The complement system is an army of proteins that help the antibodies to accomplish the attack against the invaders (microbes or toxins).

Lymphatic system

The lymphatic system is a fine network of tubes that regulates the fluid levels in the body, reacts to bacteria, and deals with cancer cells. This delicate system deals with cell products that would normally result in a disease or disorder. It absorbed some of the fats from the intestine.  

The lymphatic system is made of lymph nodes (glands) that trap microbes, lymph vessels that carry lymph, a colorless fluid that bathes the body's tissue and contains infection-fighting white blood cells, and finally white blood cells, called lymphocytes.


The spleen is a small organ inside the left rib cage and above the stomach. It is part of the lymphatic system and its job is to store and filter blood and produce white blood cells and antibodies. White blood cells, as explained above are traveling through the body to identify invaders. The spleen maintains the level of body fluid from the lymphatic system (Cleveland Clinic, 2022).

Bone marrow

Bone marrow is the tissue comprising the center and the epiphysis of bones, which is the location where the body produces new blood cells. The bone marrow produces antigen-specific antibodies and supports the immune system to grow an army of fighter cells and proteins. It is an immune-regulatory organ capable of fine-tuning immunity (Zhao et al., 2012).


The thymus is an organ that is critically important to the immune system and the location where T cells are developed. The thymus filters and monitors the blood content and produces white blood cells, T-lymphocytes.

🪫 Signs of a weak immune system

High-stress level

Stress initiates a cascade of events involving the hypothalamic-pituitary-adrenal axis (HPA) which is the primary driver for endocrine stress response. This cascade of events increases the production of glucocorticoids, which include cortisol, and is often called the stress hormone. Although this series of events is necessary when your body is in fight-or-flight-mode when stress becomes chronic the communication between the brain and the immune system is imbalanced and can lead to mental and physical health conditions, such as chronic fatigue, metabolic disorder, such as diabetes, or obesity, depression and immune disorders (APA, 2018).

Constant cold

It is said to be normal to have 2-3 colds per year and healthy adults can bounce back within 7-10 days. It takes the body about 3-4 days to produce enough antibodies to fight off the germs. But if colds become regular or it takes longer to fight off a cold, it can be a result of a weak immune system (Hasan, 2022).

Tummy troubles

Stress can affect digestion and the absorption of nutrients in the intestines. It can weaken the intestinal barrier and allow gut bacteria to enter the body. A robust immune system can fight those bacteria that don't belong in the body but when stress becomes permanent and the body is fighting with constant inflammation, the protective barrier can not withstand it. This can lead to a change in the gut microbiota, the time the body needs to move food through the gut, and/or changes in the immune responses (APA, 2018).  

Slowly-healing wounds

When having a wound, the body normally sends nutritious rich blood cells to the wounded part of the body to help regenerate new skin. If the immune system is weak, the body doesn't have enough healthy blood cells to send to the wounded body part and it takes the body longer to heal.

Frequent infections

A healthy adult doesn't have frequent infections. Signs of a weak immune system can be, when an adult has more than 4 ear infections per year, develops pneumonia 2x during one year, suffers from chronic sinusitis, or more than 3 episodes of bacterial sinusitis per year, or need more than 2 courses of antibiotics per year (Hasan, 2022).

Constant tiredness

A weak immune system comes with a low energy level. And if an adult gets enough sleep but still feels exhausted, it is possible that the immune system is working on a low mode as well. The energy is imbalanced because the body takes all the energy for the immune system to fight off germs (Hasan, 2018).

🚀 How to boost the immune system while traveling?

#1 Handwashing

Wash your hands frequently as germs and bacteria are the first invaders that can send alarms to the immune system to fight back. Instead of wasting the power of your immune system on germs from public bathrooms, keep your army on alert for more important invaders. Only 2 of 3 adults wash their hands after using a public bathroom, which is a total waste of antibodies and white blood cells to protect the body from this low-level crime.

#2 Sleep cycles

Healthy sleep cycles help the body to restore itself and produce cells, tissue, and protein, and therefore, it helps the immune system to regenerate as well. Sleep is not just important for your physical health but also for your mental health, which has a great impact on your physical health. Stress for example can reduce the quality of sleep which can reduce the quality of your immune system.

We don't have always control over our accommodation setup. But if you suffer from insomnia or noise sensitivity, make sure to invest in better accommodation that provides a better sleep setup, such as a better mattress, pillows, black-out curtains, quietness, and temperature control.

#3 Regular exercise

Physical workouts and body movement have a positive impact on our overall health, including both, physical and mental health. The oxygen which is pumped into the blood helps to produce more blood cells which are needed for the immune system's army.

In most places worldwide, you find gyms and yoga studios that allow you to join a local sports group. If the destination is surrounded by nature, go for long walks, hikes, mountain bike trips, and any other outdoor activity that supports your cardiovascular system. Local Facebook groups can be the first address to reach out to fellow sportsmen to either join an existing group or form a new one.

#4 Healthy diet

Additionally, a healthy diet supports the gut to strengthen the intestinal barrier that prevents gut bacteria to enter the body outside of the intestine. As mentioned before by regulating the cortisol intake through food, you can support the body to reduce the production of stress hormones. And stress, as mentioned above, has a negative impact on your immune system.

A healthy diet provides the body with vitamins, fats, and minerals which are part of cell production. If you are on a special diet or you have an allergy, you might want to consider taking supplements to compensate for the lack of nutrition.

Many countries provide delicious, nutritious, and fresh local food. Whether you shop at the local markets in tropical Thailand, the exotic markets in Mexico, or the nearby supermarket in your neighborhood, fresh and unprocessed food has a positive impact on your mental and your physical health.

#5 Quit smoking and alcohol

It should not be surprising that smoking and alcohol, as well as other drugs, are harming the body as the toxins are a constant alarm and stress for the body to fight back. Therefore, the immune system is in a constant fighting mode which weakens the body in the short-term but also long-term and of course can cause disease and illness, once the immune system can not handle the toxins any longer.

#6 Minimize stress

As elaborated in the above sections, stress can result in the production of anti-stress hormones which, when stress becomes chronic, create an imbalance and miscommunication between the nervous system in the brain and the rest of the body.

Stress is a complex topic as stress can be caused by personal stuff that is going on, work-related tasks and coworkers, or the overwhelming preparation for the next travel episode. Stress can result from loneliness, depression, burnout, and/or anxiety and once it becomes permanent, it gets harder and harder to get out of this downward spiral. Watch yourself, by using a mood tracker, for example, and see how often you feel stressed. Ask yourself what stresses you and try to eliminate the stress.

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