Pus in a wound

What does it mean to have pus in the wound?

Pus is a discharge from the body called exudate in response to inflammation. The texture and color of the pus can vary from thin to thick, depending on the trigger and the environment, and from pale yellow to green or even green-blue in color. In addition to its color and texture, pus also varies greatly in its smell; here, too, the bacteria involved are decisive. But pus can also develop without infection, as is the case with psoriasis postulosa, although this is rather the exception. As a rule, pus in the wound means that there has been a colonization of bacteria in the wound, which has caused inflammation and the body's own defense against this bacterial colonization is now working.

Causes of pus in the wound

The most common cause of pus in a wound is infection with bacteria. Bacteria that cause infections with pus formation are also called pyogenic bacteria. If there is a colonization of pyogenic bacteria on a wound, the body's own immune system becomes active and tries to break down the bacteria with the help of immune and defense cells. The neutrophilic, multinucleated lycocytes are of great importance here. The affected tissue is melted by the immune cells, with proteolytic enzymes being released, i.e. enzymes that break down proteins and bacteria. These melting processes and degradation products then show up as a yellowish secretion on the wounds in the form of pus.

Pustular psoriasis is a rather rare cause of pus.

Read more about psoriasis as a cause. All information about this disease can be found on Psoriasis (psoriasis)


The diagnosis of pus on a wound is a visual diagnosis, especially with a trained eye. Important features are the color from pale yellow to green-yellow to green-blue, the consistency from thin to slimy and the smell, which can vary from "odorless" to "sweet" or "fetid". These first characteristics can already give clues to the origin of the pus and the germ colonization in the wound. For precise pathogen detection, a smear is taken from the infected wound, from which the bacteria in the pus are then grown in the laboratory under artificial conditions and can be precisely identified. In addition to the exact identification of the bacteria, resistance testing is also important for further treatment; this can also be carried out on the removed bacteria and thus the ideal antibiotic can be found.

How do I distinguish pus from fibrin?

For the layperson it is often not easy to distinguish fibrin, which is a natural and important component in uncomplicated wound healing, from pus and an associated wound infection. Fibrin is a conglomerate of thrombocytes - the blood platelets - and fibrin molecules, which stabilize the blood platelets and thus close the wound tightly and protect it from contamination, heat loss and mechanical stimuli. In contrast to pus, this coating cannot simply be wiped off the wound; on the contrary, fibrin adheres firmly to the wound surface and has a rather dry character, unlike pus.
However, there is also what is known as infectious fibrin, in which fibrin and pus mix. This often happens with chronic wounds.
Due to the many variations and the possible serious complications of an advanced wound infection, a doctor should always be consulted in case of doubt in the case of unclear wound coverings and further examinations carried out if necessary.

Concomitant symptoms

Pus in a wound is only part of the inflammatory response to bacterial colonization of a wound. In addition to the formation of pus by the immune cells, there are other symptoms that are associated with a wound infection, such as reddening, overheating and swelling of the wound or pain in the affected area. In addition, a strong and sometimes unpleasant odor can develop during a wound infection with pus.


The infection in the affected tissue damages many cells which, among other things, release messenger substances such as histamine. These substances cause the blood vessels to widen around the infected wound. This mechanism is very important for wound healing, because the widening of the vessels reduces the flow rate of the blood in this area and important components of the blood, such as immune cells, can pass into the wound in large quantities. Because of this widening and thus increased blood flow to the tissue, the surrounding tissue appears reddened.


In addition to the messenger substances already described above, which are released when the tissue is damaged and ensure that the vessels widen, many messenger substances are also released that trigger a pain reaction. In the context of a severe and prolonged infection, these can be increasingly released and thus increase the sensation of pain.

Wound smells

If a wound emits an odor, this almost always indicates a colonization with bacteria. Based on the smell, you can already get initial clues as to which bacteria it could be. For example, infections with Escherichia coli and anaerobes result in a fetid odor from the pus. Infections with the bacterium pseudomas, on the other hand, usually smell rather sweet. However, many purulent wound infections are also odorless, which is why this criterion can be used as an indication, but it does not replace further diagnostics.

What is the best way to treat the wound?

The optimal wound treatment is a large field of work and is summarized in the term wound management, which includes the following points: wound history, wound physiology, phase of wound healing, the actual wound treatment, documentation of the wound and the appropriate pain therapy.

Since not every wound is the same, an important part of modern wound treatment is the previous wound history. This includes, among other things, what kind of wound is it, what caused it and which previous illnesses and possible complications are known to the patient.
The next important step is the physiology of the wound, depending on the type of wound and its location on the body, each wound has its own healing tendencies.
The next step is to decide which healing phase the wound is in; in the case of severely purulent wounds, it must also be decided whether or not a surgical rehabilitation of the infection center is not necessary.
After all of these points have been taken into account, the actual treatment of the wound begins, which is individually tailored to the wound. The basic principle of every wound healing process, however, is that the wound should be kept clean and that wound healing should be supported by gentle treatment.
In the case of larger and chronic wounds, in particular, wound documentation is of great importance in order to objectively assess the healing process and the dressings used.
Of course, pain therapy is also an important part of wound treatment; depending on the extent of the infection, sufficient freedom from pain should be made possible.

You can find more about this on our website Phases of wound healing


Betaisdona is an ointment containing povidone-iodine, which is available over the counter in pharmacies. As an antiseptic agent, povidone iodine is often used prophylactically on the skin and mucous membranes before injections or minor operations. The ointment can also be used as a disinfectant in the treatment of superficial skin injuries such as cuts and abrasions. For this purpose, the ointment can be used on the affected area several times a day for a limited period of time.

More about this ointment on our website Betaisodona

Home remedies

Home remedies are widely used in the treatment of skin wounds. A home remedy which has become increasingly important in recent years and which alternative medicine can no longer be imagined without is honey. The exact effect of honey is still not explained in detail, but honey creates an acidic environment in the wound, which damages bacteria and reduces their rate of reproduction. However, it is important that you use natural honey, after heating it once, the honey loses its healing properties.
Another popular home remedy for treating wounds that has been known for centuries is chamomile. Chamomile is also anti-inflammatory. Gentle washing or light drizzling of chamomile tea on the wound results in natural cleansing and anti-inflammatory prophylaxis.
There are many other home remedies known for wound treatment, many of which are certainly also very effective, but if a wound is heavily colonized with pus and a strong inflammatory reaction, you should consult a doctor in order to be able to treat a possible severe course in good time.

Should one always express pus?

In principle, pus should not be expressed by the layperson. By manipulating the pressure on the wound, more bacteria from the hands or the surrounding skin can get into the wound and exacerbate the infection. Other cells in the already irritated tissue are also damaged and the inflammatory reaction is increased as a result. If a wound is heavily covered with pus, it is always indicated to have it cleaned by a specialist under sterile conditions to prevent the infection from worsening.

When do I need to see a doctor?

Basically, you don't have to go to the doctor with every purulent wound. Careful wound treatment with regular dressing changes and cleaning of the wound can also be done at home. However, if the infection worsens, there is increased pus formation, increasing redness, swelling or pain, a doctor should be consulted. Even with chronically ill people, especially people with a metabolic disease that could negatively affect wound healing, you should consult a doctor at an early stage in order to obtain an assessment of the wound conditions and therapy options.


The duration of a wound infection with pus formation is always very individual and depends on the size of the wound, the strength of the bacterial colonization and the underlying health of the person concerned. In a young person without relevant previous illnesses, such as a metabolic disease or other risk factors for slow wound healing, such as smoking, a wound infection can heal within 14 days. However, if there is a serious underlying disease and reduced wound healing, a severe wound infection with pus formation can turn into a chronic infection with years of therapy. For this reason in particular, timely wound assessment and wound treatment by a specialist is important in order to get the infection under control at an early stage.