If bacteria or other pathogens enter a wound, an infection can occur. Symptoms or signs of wound infection include increasing pain, swelling, and redness. More severe infections may cause nausea, chills, or fever.

Treatment will depend on the wound type and the infection’s extent. A person may be able to treat minor wound infections at home. However, people with more severe or persistent wound infections should seek medical attention.

This article covers how to prevent, recognize, and treat an infected wound. It also covers risk factors, complications, when to see a doctor, and medical treatment.

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An infection may lead to redness and other discoloration, swelling, and pain around the wound.

Wound infections can also lead to other symptoms, such as:

Wounds become infected when bacteria enter and colonize the cut or wound. Common bacteria that may cause a wound infection include:

People can minimize the risk of infections by treating wounds effectively. Doing so will include:

  1. Thoroughly wash the hands with soap and warm water, then rinse and dry them.
  2. If there is active bleeding, hold a clean bandage or gauze to the wound and apply pressure until it stops.
  3. Clean the wound by running warm water over it for several minutes. Use warm, soapy water to clean the surrounding skin, but avoid getting soap in the wound.
  4. Make sure that the wound is free of dirt or debris, such as grass or gravel.
  5. If desired, apply a thin layer of antiseptic ointment or petroleum jelly to the cut or scrape.
  6. Allow the skin to air dry before covering it with gauze or a bandage.

Other tips

Practicing proper wound aftercare in the days and weeks after sustaining an injury can help the healing process, reduce the risk of infection, and minimize scarring. Steps to following include:

  • Change the wound dressing at least once a day. Replace it immediately if it gets damp or dirty.
  • Gently wash the wound each day.
  • Avoid using hydrogen peroxide or iodine on the wound as these may cause skin irritation in some people. Stop using other antiseptic ointments if they cause skin irritation.
  • Do not pick at the skin or the scab, as this can lead to scarring, slow healing, and increase the risk of infection.
  • See a doctor if the wound does not show improvement within 1–2 days.

More severe wound infections require prompt medical attention, particularly those with other symptoms such as fever, feeling unwell, or discharge and skin streaks from the wound.

Doctors can treat bacterial infections with antibiotics. To fully treat the infection and prevent the bacteria from becoming resistant to the drug, a person must complete the course of antibiotics.

Some wounds may require further treatment in addition to cleaning. The doctor may recommend wound cleansing solutions, specific wound dressings, or procedures to remove infected or dead tissue.

People with animal bites or wounds from dirty or rusty objects may be at risk of tetanus and need to get a tetanus shot.

Cuts, grazes, and other skin breaks can become infected when bacteria enter the wound and begin to multiply. The bacteria may come from the surrounding skin, the external environment, or the object that caused the injury.

It is important to clean and protect the wound properly to reduce the risk of infection.

The risk of wound infection is higher if:

  • the wound is large, deep, or has a jagged edge
  • dirt or foreign particles entering the wound
  • the cause of the wound was a bite from an animal or another person
  • the cause of the wound was an injury involving a dirty, rusty, or germ-containing object

Certain health conditions and environmental factors can increase the risk of infection. These include:

  • diabetes
  • a weakened immune system, such as in people living with HIV or those taking immunosuppressant medications
  • lack of mobility, for example, in people who spend most of their time in bed
  • advancing age — older adults are more at risk of wound infection
  • nutrient and vitamin deficiencies

Rarely, incision wounds from surgical procedures can also become infected. This occurs in about 2 to 4% of people who undergo surgery.

If a person does not receive treatment for a wound infection, the infection can spread to other parts of the body, which may lead to serious complications, including:

  • Cellulitis is an infection of the deeper layers and tissues of the skin, and it can cause swelling, redness, and pain in the affected area. Other symptoms can include fever, dizziness, nausea, and vomiting.
  • Osteomyelitis is a bacterial infection of the bone. Symptoms include pain, redness, and swelling around the infected area. Fatigue and fever are other symptoms that may affect those with osteomyelitis.
  • Sepsis is an extreme immune reaction that sometimes occurs when an infection enters the bloodstream. Sepsis can lead to multiple organ failures and is life threatening.
  • Necrotizing fasciitis is rare, but it occurs when a bacterial infection spreads into a tissue called the fascial lining that lies deep beneath the skin. It is a medical emergency.

A person with a wound should seek medical attention if:

  • the wound is large, deep, or has jagged edges
  • the edges of the wound do not stay together
  • symptoms of infection occur, such as fever, increasing pain or redness, or discharge from the wound
  • it is not possible to clean the wound properly or remove all debris, such as grass or gravel
  • the cause of the wound was a bite or an injury from a dirty, rusty, or dirty object

A person should seek urgent medical attention if blood is spurting from the wound or if applying pressure to the wound does not stop the bleeding.

How do I tell if my wound is healing or infected?

Signs that a wound is not healing properly and may be infected include feeling warm to the touch, swelling, discharge or pus, long lasting pain, or fever.

Can an infected wound or cut heal on its own?

Some minor wound infections can heal independently, but if a wound starts to develop more drainage, the surrounding redness spreads, or if a person develops a fever, they should seek further medical attention.

How do I know if I have necrotizing fasciitis?

Fever and severe pain are early symptoms of necrotizing fasciitis. The infection spreads quickly to adjacent tissues. The skin changes in color. It becomes firm, shiny, and warm. After a few days, the skin breaks down with blisters and dead tissue. However, neither a person nor a doctor can diagnose necrotizing fasciitis from symptoms alone; instead, imaging or biopsy tests are required to confirm the diagnosis.

A wound infection can occur if bacteria enter and multiply inside the wound. Immediately cleaning and dressing cuts, grazes, and other small wounds is the best way to prevent infections. However, people with larger, deeper, or more serious wounds should have a trained healthcare professional treat the injury.

The signs and symptoms of wound infection include increasing pain, swelling, and redness around the affected area. A person may be able to treat a mild infection of a small wound at home by recleaning and redressing the wound.

However, more severe wound infections require prompt medical attention, particularly with fever, feeling unwell, or discharge and red streaks from the wound.

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