Wounds

ByJaime Jordan, MD, UCLA School of Medicine
Reviewed/Revised Jul 2024
VIEW PROFESSIONAL VERSION

Cuts or tears in tissue (lacerations), scrapes (abrasions), and puncture wounds can be caused by bites or by other mechanisms. Wounds that are not caused by bites and are clean and relatively small usually heal rapidly without any problems. However, some wounds can cause extensive blood loss.

In some wounds, deeper structures, such as nerves, tendons, or blood vessels, are also injured. Other wounds can become infected. A piece of foreign material (such as a splinter, glass, or a clothing fragment) can also remain hidden inside a wound, causing later problems such as infection.

Shallow cuts to most areas of the skin rarely bleed much and often stop bleeding on their own. Cuts to the hand and scalp as well as cuts to arteries and larger veins often bleed vigorously.

Did You Know...

  • Even shallow cuts to the scalp or fingertip may bleed vigorously.

Infection can develop when a wound is contaminated with dirt and bacteria. Although any wound can become infected, infection is particularly likely in deep scrapes, which grind dirt into the skin, and in puncture wounds (particularly those resulting from animal bites or human bites), which introduce contamination deep under the skin. Also, wounds that contain foreign material frequently become infected. The longer a wound remains contaminated, the more likely it is that infection will develop.

Wounds can be painful at first, but usually the pain lessens after the first day. If a cut affects a nerve or tendon, the person may be unable to move the body part fully. Some nerve injuries cause weakness or paralysis, loss of sensation, or numbness. If foreign material remains inside a puncture wound, the part of the wound near the material is usually painful when touched.

Pain that worsens a day or more after the injury is often the first sign of infection. Later, an infected wound may become red and swollen and may ooze pus. A fever may also develop.

Necrotizing skin infections are rapidly progressing infections that threaten life and limb that can occur even after a very minor skin wound.

First Aid for Wounds

The first step in treating a cut is to stop the bleeding. Visible bleeding can almost always be stopped by placing a gauze pad or clean cloth over the bleeding area and firmly compressing the area with a finger or hand for at least 5 minutes. Whenever possible, the bleeding part is elevated above the level of the heart.

If the bleeding is on an arm or leg and continues after pressure has been applied, a tourniquet can be applied by anyone who has been trained to use one. This is usually required only in severe injuries (for example, gunshot wounds, deep penetrating stab injuries, large deep cuts, or amputations. Tourniquets should be used only until the person can be evaluated and treated by a doctor. (See Stop the Bleed.org for additional information on tourniquet use.)

To prevent infection, dirt and particles are removed and the wound is washed. Large, visible particles are picked off. Smaller dirt and particles that cannot be seen are removed by washing with mild soap and tap water. Gentle scrubbing may be required to cleanse deep scrapes. Colder temperature water may allow the blood vessels to constrict, helping to slow the bleeding. Dirt and particles that remain after washing often can be removed with a more highly pressured stream of warm tap water. Harsher agents, such as alcohol, iodine, and peroxide, are not recommended. These solutions can damage tissue, impairing the capacity to heal.

If a wound is very small, it can be kept closed with first aid tape or skin adhesive (products that are used specifically for closing a small wound). Stitches may be needed for deep or large cuts. Stitches should be placed only by a health care professional. After cleansing and, if necessary, closing the wound, antibiotic ointment and a bandage are applied. Antibiotic ointments should not be applied if specialized tape or skin adhesive has been used for wound closure.

Medical assistance is needed under the following circumstances:

  • If a cut is longer than about ⅓ inch (¾ centimeter), is on the face, appears deep, or has edges that separate

  • If bleeding does not stop on its own or within several minutes after pressure is applied

  • If there are symptoms of a nerve or tendon injury, such as loss of sensation or loss of movement

  • If a scrape is deep or has dirt and particles that are difficult to remove

  • If there is a puncture wound, particularly if foreign material in the wound is likely

  • If the person has not had a tetanus vaccination within the past 5 years

All wounds, whether treated at home or by health care professionals, should be observed for symptoms of infection (worsening redness, tenderness, warmth, or drainage of pus) during the first several days after treatment. If any symptoms of infection develop (such as fever, pus in or leaking from the wound, or redness increasing around the wound), medical assistance should be sought as quickly as possible (within several hours).

Most small wounds heal within a few days.

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