Infection – Causes, Symptoms & Treatment


An infection is the body’s defense against invading microorganisms such as viruses , bacteria or fungi . This results in infectious diseases with and without clinical symptoms. The range of infectious diseases is very large, ranging from common childhood illnesses to serious infections that threaten life.

What is an infection?

Infection is caused by microorganisms attacking the body. The pathogens multiply quickly and spread throughout the body. The body tries to fight off the spread and fight the pathogens, causing an infection.

Not all bacteria that surround us make us sick. In the gut or on the skin , they even ensure that we stay healthy and that digestion works properly.

In healthy people with a good immune system , most infections have only mild symptoms. The immune system recognizes the attackers and fights them. Harmless germs are permanently on our skin, in the digestive tract or on the genitals and do not cause any harm to healthy people.

If the person concerned is weakened by another illness, his or her organism becomes unbalanced. A defense reaction occurs that weakens the organism. Depending on how strong the immune system is, different symptoms appear. If the defense reaction is too weak, the microorganisms spread further, spread through the bloodstream to important organs and lead to generalized sepsis.


Germs are everywhere in our environment and can enter the body in many ways. We pick them up by swallowing , touching organic waste, cut fingers, sneezing or hand contact and droplet infection with infected people. There is also a risk of infection during surgery.The immune system protects us from infections because we are constantly being attacked by viruses and bacteria. If it is weakened or the number of aggressive germs is too high, the defense doesn’t stand a chance. An infectious disease occurs. Allergies , infections and autoimmune diseases weaken the immune system.

However, the human organism’s defense system against external attacks is complex. On the one hand, we have anatomical barriers such as the mucous membranes , the first instance against attacks. Contrary to what is often assumed, excessive hygiene does not protect against infections, but makes us more susceptible because the natural barrier is destroyed.

The second instance is the body’s immune system. Everything that appears threatening to the body is destroyed by the immune cells. The defense reaction usually manifests itself with fever . The normal human temperature is between 36 and 37.5 °C. From 38 °C one speaks of fever. Above 41 °C, the body temperature becomes life-threatening as cells are destroyed. Fever is a very important but by no means always present symptom of an infectious disease.

The immune system also has a memory. After an infection, the immune system becomes stronger because the body can remember certain germs. This protective mechanism works in the same way as with a vaccination . The vaccination fools the body into being infected with germs, so that the body develops antibodies. If the person is later actually attacked by this pathogen, the antibodies react to it. However, over time, this memory fades.

In the case of allergies, the body’s defense system is not fully functional. In the case of a house dust mite allergy or hay fever , the defense is directed against substances that are basically harmless. Most people who inhale these substances feel nothing. An allergic person has no protective antibodies and shows allergic symptoms. In this case, the immune system does not have the ability to learn a defense reaction and to react to the substances in the future.

Symptoms, Ailments & Signs

Infectious diseases are caused by pathogens and they occur in a very wide range. Infectious diseases range from a simple cold to typical childhood diseases such as measles , chickenpox and rubella to HIV or tropical diseases . Colloquially they are also called infections, but should not be confused with an infection. Infection is the inflammation of a wound.

Infectious diseases are accompanied by a wide range of symptoms and have different time courses. They are differentiated according to the origin of the pathogen, the entry point of the pathogen, the course of the infection or the transmission route. The extent of the infection can also be a distinguishing criterion.

Infectious diseases are most commonly caused by bacteria. Bacteria are responsible for tuberculosis , meningitis , cholera , plague and Lyme disease , for example . Whooping cough and diphtheria are also transmitted by bacteria and can be life-threatening for small children. Lockjaw ( tetanus ) is triggered by very resistant bacteria.

Fungal diseases are often found on the eyes , oral mucosa and genitals.

All classic childhood illnesses as well as hepatitis B , flu , colds , many colds and AIDS are caused by viruses. Hepatitis B is a contagious liver disease that quickly becomes chronic. Shingles is caused by the same virus as chickenpox , but is much more dangerous.

Depending on whether fungi, viruses or bacteria are the triggers, there is a different therapy. For treatment, the pathogen must first be determined. You can protect yourself against some pathogens by vaccination.

However, the most sustainable way is to protect yourself with a strong immune system, which can be positively influenced. We can strengthen it through a balanced diet with fresh fruit and vegetables and exercise in the fresh air. In addition to vitamins , the supply of minerals such as zinc , iron , calcium , potassium and selenium is also important.

Bacterial infections are often dangerous and are often treated with antibiotics . Antibiotics do not help with viral infections. However, there are other drugs that stop the virus from multiplying.


In most cases, infection is caused by bacteria, which can cause various complications. Severe and long-lasting headaches often occur in connection with an infection, which can only be eliminated with the help of appropriate medication. Other possible side effects are an elevated temperature, fever, nausea, vomiting and severe sore throat or difficulty swallowing.Anyone who leaves these individual clinical pictures without treatment is of course taking a great risk, so that a significant deterioration can be expected. However, if you resort to treatment with the right medication at an early stage, you can significantly alleviate and combat the symptoms mentioned above.

However, those who do not initiate treatment must expect considerable complications. The symptoms will increase significantly within a short time, so that the infection will spread throughout the body. It is not uncommon for severe flu to develop in this context, which poses a great risk if left untreated.

Anyone suffering from a bacterial infection should always resort to drug treatment. This is the only way to avoid serious complications and symptoms. If left untreated, the above complications will worsen significantly.


Follow-up care in the event of an infection depends on the specifics of the infectious disease that has gone through. Infections of the skin, the gastrointestinal tract and the upper respiratory tract show, for example, how different post-infection care can look like. While in the case of superficial infections of wounds it is important to enable rapid regeneration by avoiding contamination, after internal infections the restoration of the immune system is often an important factor in aftercare.

This includes getting enough sleep, a healthy diet and drinking enough water. Avoiding nicotine and alcohol is advisable. In the case of infections of the respiratory tract, aftercare can also consist of ensuring fresh air, for example by consistently airing the rooms or taking regular walks. In the case of gastrointestinal infections, the body often has to slowly get used to the usual food again.

Small portions and avoiding alcohol and nicotine are advisable during the regeneration phase. In infections treated with antibiotics, those affected often complain of a disturbed intestinal flora. Ideally, patients pay attention to a light diet, which should include avoiding spicy or fatty foods. Yoghurt products, possibly taken in consultation with the doctor, can help to rebuild the intestinal flora.

Exercise caution should be exercised. These should only be resumed when the infection has completely subsided and the patient is fit again.

Outlook & Forecast

The prognosis of infection is favorable. When medical care is sought, the spread of the pathogen is stopped as quickly as possible. The triggering germs then die off and are transported out of the organism. Regeneration begins and the body’s own strength is gradually built up. With a stable immune system and sufficient rest, there is a complete freedom from symptoms within a few weeks.

Delays in the recovery process can be expected if the patient already has another disease or does not have a healthy immune system. Naturally, this occurs in children or elderly patients. Impairments must also be expected with an unhealthy lifestyle. Without adequate medical treatment, the prognosis for these sufferers worsens.

In severe cases, premature death can occur because the organism is weak and can no longer recover sufficiently due to the various impairments. The pathogens spread almost unhindered and the organism finally capitulates because of the large number of germs.

Adults who lead a healthy lifestyle and do not have any other illnesses usually experience relief from their symptoms without medical treatment. Taking into account various self-help measures and with the support of well-known home or natural remedies, healing can be documented in a large number of those affected.

You can do that yourself

What a patient can do themselves in the event of an infectious disease depends on the nature of the symptoms. The most common are infectious diseases that are accompanied by cough, hoarseness, runny nose, headache and fever and are usually subsumed under the collective term “cold”. Anyone who has a cold should, if possible, allow themselves a few days of rest , drink a lot, keep warm and eat healthy, easily digestible food rich in vitamins. Taking vitamin C can also strengthen the immune system. Over-the-counter medicines from pharmacies help against minor side effects such as coughs or runny noses . However, as soon as the symptoms get worse, a doctor should be consulted immediately. 

In autumn and winter there is also a regular outbreak of influenza. The symptoms are often very similar to the common cold, but the flu is far more aggressive and the course is usually much more severe and lengthy. In addition, influenza is usually highly contagious. For this reason alone, the workplace should not be visited and a doctor should be consulted instead. Home remedies can also help against the high fever that often accompanies the flu . In particular, cold calf wraps quickly provide relief. Vaccination against many influenza pathogens are also offered, which people who belong to a risk group should also take advantage of.

When should you go to the doctor?

A doctor is needed if the person concerned has a feeling of illness. Since the symptoms increase sharply in most cases within a short period of time in the case of an infection, a doctor should be consulted as soon as the first signs appear. If you develop an elevated temperature, fever, sweating, tiredness, vomiting or dizziness, it is advisable to consult a doctor. Stomach problems, indigestion, diarrhea or nausea should be evaluated and treated. A doctor must be consulted in the event of persistent loss of appetite, general weakness, diffuse pain or reduced performance. If sleep problems set in, if there are heart rhythm disorders, listlessness or apathy, a doctor should be asked for help.

If you have a racing heart, high or low blood pressure or a strong feeling of cold or heat, you should consult a doctor. Changes in the complexion, swelling of the skin or redness must be examined and treated. If you have a headache, listlessness, red eyes, breathing difficulties or a persistent cough, consult a doctor. If the person affected suffers from a cold, difficulty swallowing, sexual dysfunction or irritation of the skin, a doctor should be consulted. If pus forms, there are open wounds or psychological problems, it is advisable to clarify the symptoms. If existing symptoms increase or spread throughout the body, a doctor should be consulted immediately.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.