Building up the immune system: the most important questions and answers

Immunsystem aufbauen: Die wichtigsten Fragen und Antworten

There are many questions about how best to build up your immune system. After the flu, taking antibiotics or chemotherapy, this topic is of great importance. If you belong to one of these groups, you should definitely read on.

In our article Building the immune system: the most important questions and answers, we will bring you some facts closer. We try to create clarity on the subject, whereby we have always examined the advantages and disadvantages in a well-founded manner.

the essentials in brief

  • The immune system is very important for our body. It ensures our general well-being and can be enhanced with various vitamins and minerals.
  • A balanced diet is the key to a strong immune system. This applies not only to humans, but also to dogs, cats and horses.
  • The immune system is most affected by everyday life. Stress, little sleep and poor hygiene increase our risk of catching a cold. If you reduce these factors, nothing stands in the way of a healthy life.

Why is a strong immune system important?

The immune system serves to protect the body. It is important not only for you, but also for every other living being. You can divide the immune system into several subsystems.

smiling woman outdoors

A healthy immune system is important for our body. If you take care of it, you can go on adventures without worrying about getting sick. Still, it's good to be sick every once in a while as it allows your immune system to evolve (Image source: Candice Picard / unsplash)

Each of these systems is responsible for a specific task. Still, they all have something in common - they protect you. The immune system releases various messenger substances to chemically damage invaders.

The main tasks of the immune system are (1):

  • To neutralize harmful substances
  • To fight pathogenic changes in the body such as cancer cells
  • Destroy and remove bacteria, viruses, fungi

The stronger your immune system is overall, the better protected you are from potential diseases, fungi, viruses or parasites. If it is damaged, the risk of contracting such pathogens increases greatly.

As for how long it takes to rebuild your immune system, we can tell you that such processes can take months. Chemo patients are particularly hard hit.

If you suffer from an autoimmune disease, you should behave differently. It's bad to have a strong immune system at this point, because your immune system attacks organs and your body's own cells.

How does the immune system work?

The immune system consists of several organs, cells and various proteins. It is only when this complex system is damaged that there is a risk of becoming ill. (1)

It can be activated by different aspects. These are often things that the body does not see as its own. Antigens on bacteria, fungi or viruses can be the trigger.

We have linked a good video about the functions of the immune system here. You should find out everything you need to know there.

If the immune system has already come into contact with the antigens, it will fight them more quickly if the disease returns. This is because it recognized the antigens. In this way, it was able to develop antibodies against it over a certain period of time.

The immune system consists of two subsystems. Both are extremely important.

  1. The innate system defends you against common diseases. It uses phagocytes to do this. These scavenger cells protect your body from invaders via the skin or intestines.
  2. The system you've learned can create antibodies to fight diseases you've been infected with before. Since this system is constantly evolving and individually adapting, it can also successfully fight viruses that change over time.

Both subsystems are in close contact with each other. This is the only way to successfully combat germs and dangerous substances.

When is the immune system weakened?

A weakened immune system can have several causes. The most common reasons are, for example, constant stress or lack of sleep. But allergies or the wrong diet can also lead to a malfunction of the immune system. (2)

Woman lying on the bed and blowing her nose

Nobody really wants to be sick. Be it due to a common cold or other circumstances. You can either treat this with medication, enough sleep, water and the right diet. (Image source: Andrea Piacquadio / pexels)

Always remember that getting sick every now and then is not a bad thing. Your body needs diseases to develop its defenses. So don't get too caught up on the subject.

Everyday Influencing Factors

In the following list, we have highlighted the most common causes of a weak immune system during everyday life.

  • Stress is one of the most common reasons for a weak immune system. But why does stress weaken the immune system? When you are exposed to chronic stress, your body reduces the release of hormones that activate the immune system. So you get sick more often. (3)
  • Not getting enough exercise can be the reason for a weak immune system. Due to insufficient physical activity, cells become inactive and no longer protect you. (4)
  • Put simply , not getting enough sleep can lead to increased stress levels. You already know what happens then. (5)
  • Dehydration can have a significant impact on your immune system. You are made up of up to 75% water. When there isn't enough of it, your body doesn't function properly. (6)

The above points are probably the ones that affect almost everyone. Other aspects would be smoking, alcohol consumption and nutritional deficiencies. All of these factors affect whether you have a strong or weak immune system.


We consume countless foods every day and often do not realize how harmful they are to us. Here is a list of foods that can weaken your immune system.

Groceries Description
alcohol Alcohol consumption not only damages your brain but also your immune system. For example, ARDS, sepsis and cancer can develop unhindered.(7)
Salt Too much salt leads to high blood pressure and water retention in the body. You should at least know that. But consuming too much salt can lead to serious bacterial infections as the immune system shuts down. (8th)
Sugar With smaller amounts of sugar, not only your health and psyche will thank you, but also your immune system. Increased concentrations of bacteria in the body have been found for a short time after ingesting large amounts of sugar. (9)
caffeine Large amounts of caffeine can promote inflammation in the body because we don't get enough sleep. Caffeine is supposed to keep us awake, but it is bad for our health. In addition, they are often mixed with sugar or sweeteners. (10)

All statements are backed by sources if you want to find out more.

As you can see, you should do without some things so that things get better. Of course, a balanced diet is important and you don't have to do without everything completely. However, reducing consumption can not hurt.

Pre-existing conditions / allergies

Now that we've gone through the foods, we're not done listing reasons why your immune system might be weakened. We would also like to address the most important diseases that can be a cause of weakness.

Diseases often only develop as a result of errors in your immune system. But it can also be weakened beforehand.

  • SCID or combined immunodeficiency occurs in newborns. Due to the lack of important white blood cells, such children are particularly vulnerable to viruses and bacteria.
  • Temporary immune deficiencies can be triggered by various drugs such as chemotherapy.
  • Allergens are caused by proteins that the immune system classifies as hostile. In the worst case, an inflammatory reaction occurs and your immune system fights against the allergy. Then it is more susceptible to other diseases.
  • AIDS/HIV is an infection that destroys important white blood cells. As a result, the immune system is extremely weakened and those affected can hardly fight diseases that would not be a problem for normal people.

There are many more diseases that weaken your immune system, but let's cover the most important ones here. Anyway, now you know when your immune system is weakened. If you are still unsure, you can have it checked.

How can I have my immune system checked?

You can have your immune system tested in a number of ways. It is most reliable if you do a blood test. This can also be examined in different ways.

We start from the simplest case. A certain amount of blood is examined under the microscope on a grid. There, erythrocytes, thrombocytes and leukocytes are counted.

For us, the leukocytes, i.e. white blood cells, are the most important. A healthy value is between 4,500 to 11,000. In the case of inflammation, the value can quickly rise above 11,000. If you are suffering from cancer, for example, it is sometimes 2,000.

Elevated concentrations of white blood cells can also result from medication, smoking or after surgery. Low values ​​are based on bone marrow insufficiency, liver diseases or stress.

How can I build up the immune system?

Building the immune system can be a big challenge. There are different ways you can go about mastering them. Either you do it through a balanced diet, supplements or look for the medication.

Here's a look at some supplements and foods that the Cleveland Clinic says can help you with the task.

substrate Description Groceries
vitamin C Vitamin C should be known to many. The ascorbic acid helps to maintain the function of the immune system after physical exertion. Citrus fruits, broccoli, Brussels sprouts
Vitamin A Carotenoids that you absorb through such foods are converted into vitamin A. These have an antioxidant effect that helps your immune system fight disease. Carrots, Sweet Potato, Pumpkin
Vitamin D Vitamin D is important for bone metabolism and forms important proteins to strengthen our immune system. Oily Fish (Salmon, Herring), Sunlight, Supplement
vitamin E Vitamin E, similar to vitamin C, is an antioxidant, which can help you fight disease. Broccoli, hazelnuts, almonds, sunflower seeds
zinc Zinc can prevent an overreaction of the immune system. If there is an infection in your body, it is possible that a large focus of inflammation forms. Zinc prevents this and allows the immune system to work more slowly. Oysters, Crabs, Lean Meats
selenium Selenium works in a similar way to zinc. It reduces overreactions of the body after detecting cancer cells. Broccoli, garlic, tuna, sardines
iron We mean the special form of the heme iron. Heme iron strengthens your immune system because it is more bioavailable than regular iron. But you should not exaggerate here. In large quantities, it can be extremely harmful. Lean Meats, Seafood, Beans, Broccoli

You should know enough foods to help you maintain a healthy immune system. The same applies here - do not eat everything in unbridled quantities. It is important to have a balanced diet and to give your body enough variety.

If you are looking for even more alternatives, you can watch this video. The effect of individual foods is explained in more detail here.

If that is too complicated for you, you can also strengthen your immune system with medication. Alternatively, you can build up your immune system with a cure. The options are entirely up to you.

How can I rebuild my immune system after chemo?

The answer to the question is as simple as it is obvious - supply your body with the necessary micronutrients. Chemotherapy attacks the immune system very severely and costs the body a lot of strength.

You can strengthen your immune system with the right diet or supplementation with the necessary minerals and vitamins. However, there is still a risk of developing cancer again.

Don't get your hopes up too high when you're carefully taking care of your immune system post-therapy. Rebuilding can usually take months. Medications can also help you, but depending on the type of cancer, they can also be harmful.

Consult with your local doctor about the structure of your immune system. He should know what you can do and how so that you feel better faster.

How do I rebuild my immune system after antibiotics?

Our immune system is in the stomach - at least that's what they say. There's a lot of truth in that too. Trillions of bacteria keep us healthy. However, these bacteria can be destroyed during antibiotic therapy.

Antibiotics are designed to specifically attack bacteria that damage our body. The intestinal flora is also affected. You can counter this by taking probiotics.

Probiotics are the preparations if you want to give your immune system a boost. They contain important bacteria and microorganisms.

You can also create a probiotic effect with conventional foods. Examples of such foods are:

  • linseed
  • psyllium
  • yogurt
  • Chicory
  • salsify

If you don't like it, you can always use supplements. But you should always try.

The foods themselves will not have much of an effect unless other factors are right. You should also eat a varied diet with fruit and vegetables, drink enough water and exercise regularly.

How can I rebuild my immune system after cortisone treatment?

Cortisone can have serious side effects over the long term. Among other things, it weakens the immune system. It shows similar effects as antibiotics. It destroys bacteria but cannot distinguish between good and bad.

When the good bacteria that keep fungal infections in check are destroyed, they are free to multiply. This is how the immune system intervenes to stop the multiplication of the fungi.

Due to an uncontrollably multiplying intestinal fungus, the body falls victim to other diseases more easily. If such things are left untreated, severe inflammation of the mouth, rectum and esophagus can occur.

According to the Aachener Zeitung, four out of five people have fungal pathogens in their intestines. According to Professor Richard Raedisch, there is often no problem with it. You only have to do something when the number of germs shoots up to worrying heights.

How can I build up the immune system of pets?

Building up a pet's immune system can be quite a problem. So far, research has only been done on mice to understand their immune system. (11) Therefore, we invoke the basics of animal care and how you should treat your pet.

Since there is little to no scientific evidence or studies on boosting pets' immune systems, now is the time to learn how to properly care for them. Good care is usually enough for the animals to keep them healthy.

Owning a pet such as a dog, cat or horse can also benefit our immune system. For example, petting the animals reduces stress and makes us feel better.


Many questions arise about the dog - man's best friend. But how can we ensure that his immune system is always at its best? To achieve this, you just need to follow a few tips.

  1. Cleanliness : Hygiene is just as important for dogs as it is for humans. Wash your dog regularly to rid him of bacteria and parasites. However, you shouldn't overdo it. Otherwise you can even weaken his immune system.
  2. Weight : The heavier your dog is, the harder it is for his immune system to fight off pathogens. Dogs live through movement. If this privilege is taken away from them, they can become very ill.
  3. Diet : A good diet naturally also ensures a good weight. Antioxidants, vitamins and minerals are also of great importance for dogs. You can also feed him broccoli or apples.

Regular visits to the doctor are also very important. Doctors check your dog's immune system and check him for various diseases during regular examinations.


Cats have an immune system similar to that of dogs. One of the differences is that cats' immune systems are better all around than dogs'. This is due to careful grooming. In cats, you have to approach the strengthening of the immune system a little differently.

  1. Stress : The most serious contributor to a weak immune system in cats is stress. This is triggered by territorial behavior. Cats always have to fight for their territory. If this factor can be minimized, your cat should be significantly better off.
  2. Nutrition : Vitamins, minerals and antioxidants also play an important role in cats. Therefore, make sure that you eat a healthy and balanced diet so that your pet does well.
  3. Play : Exercise is important for house cats. This is usually difficult to achieve in a closed apartment. You should therefore spend enough time with your animal to reduce its weight and get its circulation going.

As with dogs, you should take your cat to the doctor from time to time. Otherwise, the best way to boost your cat's immune system is with good care and proper handling. If your cat is allowed to play freely and is exposed to little stress, it should actually hardly get sick.


Horses are becoming more and more established in today's society. Especially with young girls, they are the trend as pets. Then the question arises, how can I strengthen my horse's immune system?

Normally, horses move sufficiently independently and you regularly take care of their grooming. How else can you contribute to your horse's health? It's about the diet. You can feed horses some special things to make them feel better all the time.

  1. Green Algae : Green algae reduced the risk of allergies in horses. It also reduces respiratory problems that some horses suffer from. In order for your horse to enjoy its benefits, add small amounts to the feed at first and increase over time.
  2. Rose hips : These fruits give your horse a boost of vitamin C and copper. Both things are essential for a healthy immune system. A good side effect is that it strengthens the hooves.
  3. Dandelions : Also known as buttercups, dandelions are high in vitamins A, B and C. Whether you feed them dried or fresh, they are always healthy and essential for a healthy immune system.

As you can see, you can keep horses healthy through nutrition. However, it is also questionable whether this is actually necessary. As with dogs and cats, they should be fine without a diet specially designed for their immune systems if you take good care of them.

How can I build up my baby's / child's immune system?

You have already learned that the immune system consists of two parts. One of them is the learned immune system. This only develops in children and babies as they grow up.

Maybe this video can also help you. Here are some tips for your baby to take with you.

Hygiene is important with children, but should not be overdone. From time to time, children have to get infected with things and also play outside in the fresh air. For example, later they are less likely to be affected by allergies. (12)

With a healthy diet, enough fresh air, exercise and little stress, your child can grow optimally. This not only ensures a healthy immune system, but also a healthy future.

How can I strengthen my immune system in everyday life?

Boosting your immune system through everyday life may be the smartest decision you can make about it. We've already given you a few things. Nevertheless, we will briefly repeat them here.

Our top 5 tips for a strong immune system

As a small summary, we will now give you our tips on how to strengthen your immune system.

Tip 1: This is how you can strengthen your immune system by reducing stress

Chronic stress weakens your immune system and makes you more susceptible to illness. Therefore, it is advisable to learn how to relax in stressful situations. Meditation and yoga can help you with this.

Tip 2: Regular exercise to activate your immune system

Sport is healthy for body and mind. 30 to 45 minutes of exercise a day at a heart rate of 180 beats per minute, minus your age, should give you an optimal training effect according to the rule of thumb.

This not only strengthens your immune system, but also increases your resistance to stress and improves your circulatory system.

Tip 3: Strengthen the immune system by getting enough sleep

While you sleep, an unbelievable number of processes happen in your body that it needs to regenerate. One of these processes is the formation of immune cells.

When you sleep, your body renews its defenses so that you are protected against viruses and bacteria the next day.

Tip 4: Hygiene for a healthy body

Proper hygiene can protect you against pathogens. However, not everyone has good hygiene.

Thorough hand washing for more than 30 seconds, several times a day, you lay a solid basis to be able to fight against pathogens. Alternatively, you can help with disinfectant.

Tip 5: Sufficient sun to boost your immune system

Vitamin D is incredibly important for our body and immune system. In the winter and autumn months, it is worth taking vitamin D supplements.

In this way, you not only strengthen your immune system, but also get in a better mood. Vitamin D is particularly suitable for office workers or night shift workers.

If the tips were not enough for you, you can also fall back on suitable foods and supplements. Aronia berries, for example, can be a good option.

The aronia berry has a high content of folic acid, iron and vitamin C. There is also the possibility that it can lower blood pressure and help to stabilize the immune system.

Can I improve my immune system with homeopathic remedies?

Homeopathy is a highly controversial topic. We would therefore like to say in advance that we do not want to speak out for or against it. (13.14)

One can try to take homeopathic remedies and also experience an improvement in the immune system. However, studies have not been able to prove the effect of homeopathic remedies. (15.16)

Similar results were recorded in comparison groups with placebo as with homeopathy. This led to improvements, deterioration and no change in the immune system.

There is little research in this area, but there are pros and cons. Here you have to decide for yourself to what extent you represent the effects of homeopathic remedies.


There are a few solutions on how to build up your immune system. How you do it is up to you. We find a balanced diet and supplementation of some vitamins and minerals such as vitamin D to be the best option.

Since there are many ways you can improve your immune system, you have to find the path that works best for you. Actually, you can't do much wrong with the topic, which is why we hope the best for you.


  1. The immune system plays an important role in protecting your body. It defends you from dangerous substances, pathogens, viruses and fungi.
  2. The immune system is the first line of defense against bacteria and viruses. It consists of lymph nodes and vessels that transport our white blood cells. The system is generally very prone to errors or overactivity.
  3. The release of stress hormones in fight-or-flight situations from our ancestors shows positive changes in our immune system. The more often they were exposed to stress, the better their immune system developed. However, further research is needed to support the thesis.
  4. Sleep and the circadian rhythm are extremely important for a healthy immune system. The basis of this is the communication between the CNS and the immune system via neurotransmitters. During sleep, information is stored by viruses and bacteria and repellents are formed against them.
  5. Movement of the body leads to a widespread hormonal release and activation of cells. This strengthens the immune system and also reduces the aging process. In the future, further research is to be carried out so that optimal training plans can be designed for several individuals.
  6. Hydration plays a more important role in the immune system than the availability of energy in the cells. In order for osmosis to take place, the body must be sufficiently hydrated. In this way, nutrients can be transported very well into the cells.
  7. Alcohol leads to a blockage of immune pathways that cannot really be explained yet. In any case, this reduces the body's ability to defend itself against viruses and pathogens.
  8. Tests have been conducted on mice that have been given high levels of salt. It was found that these suffered from more and more severe infections than comparison mice. The same was found in a volunteer who consumed more than six grams of salt a day.
  9. Test subjects were each given 100 grams of sugar, with bacterial concentrations in the body rising rapidly after each ingestion. It was found that processes of phagocytosis were hindered by the sugar.
  10. Increasing the amount of sleep during infections gives feedback to the immune system to defend against the viruses more efficiently, or to only focus on them during sleep. This was concluded from the fact that sleep disorders lead to increased inflammation and infections in the body.
  11. Immune research in animals is not yet very advanced, since mice cannot provide all the necessary conclusions in this area. In the future, farm animals will provide clarification when analyzing their immune systems. In general, one can say that such animals are better protected against diseases than "non-free-living" animals.
  12. Children are increasingly affected by allergies. Finally, a good countermeasure is not to isolate children from the outside world. Children who pay too much attention to hygiene are at a greater risk of developing allergies later on.
  13. Homeopathic remedies are only studied to a limited extent. Researchers look at whether homeopathic remedies can have the same effects as normal medicines. So far, no significant effects have been proven, but this could change with further and more intensive research.
  14. Homeopathic remedies are highly controversial. Over the past 30 years of research, pragmatic equivalence trials have shown no difference between homeopathy and regular medication. Due to the fact that the sample size was only very small, further research must be carried out so that conclusions can be drawn.
  15. Homeopathic remedies have not shown any advantage over placebo drugs in the treatment of respiratory infections. Homeopathic remedies have therefore shown no effect whatsoever in the treatment of this infectious disease.
  16. The Similia Principle deals with the effects of homeopathic remedies on specific individuals. So to speak, medicines that are perfectly tailored to the person. Thus, these agents could communicate with the immune system and stimulate naturally occurring diseases in the body. So far this is just a concept, but further research could make it a reality.
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