Bleeding is the loss of blood from arteries, veins, or capillaries that either spreads out under the skin and seeps into body tissue and cavities (internal bleeding) or escapes through a natural body opening (e.g., mouth, nose, etc.) or a break in the skin (external bleeding).
You can estimate bleeding severity by assessing patient signs and symptoms, including the amount of blood loss, the degree of shock, and the level of consciousness. You must control external bleeding because significant blood loss can damage body systems and even cause death. For more information about bleeding and blood loss, go to Wikipedia or Medline Plus.
To get information about setting up a CPR/First Aid Training Course, go to CPR and First Aid courses.
Perfusion is the process by which a fluid such as blood is forced through an organ or tissue by way of vessels for the purposes of carrying oxygen and nutrients to the cells and removing waste products. Perfusion is a natural process, or it can be manufactured artificially. One example of artificial perfusion is CPR. Other examples include artificial blood pumps used during open-heart surgery and extra-corporeal circulation for artificial organ support. The entire body requires perfusion, but various parts of the body need it to differing degrees. For example:
- The heart is especially sensitive to the lack of perfusion, stopping almost immediately.
- Both the brain and the spinal cord can only last about 4 to 6 minutes without perfusion.
- Kidneys can survive about 45 minutes.
- The skeletal system can last up to 2 hours.
The body’s circulatory system causes perfusion of blood in the cardiovascular system and lymph in the lymphatic system. Shock, characterized by inadequate blood flow to all parts of the body, is sometimes known as hypoperfusion. Two types of shock that result from low levels of blood are hypovolemic shock and hemorrhagic shock.
Go to the Pathophysiology page for more information about shock.
Internal and external bleeding takes on different characteristics based on the type and size of the blood vessel(s) compromised.
- Capillary bleeding – This is the most common type associated with small, superficial injuries. Capillary bleeding features dark blood that causes a small bruise under the skin or oozes from the wound, usually clotting spontaneously.
- Venous bleeding – Bleeding from a vein is often more serious because veins are larger, they carry more blood, and it takes a more severe injury to damage them. Venous bleeding features dark blood that creates a localized hematoma or flows steadily from a larger, deeper wound than a capillary bleeding injury.
- Arterial bleeding – Arterial bleeding is the most urgent type because it is under pressure from the heart and usually occurs because of a severe, traumatic injury or deep wound. Along with venous bleeding, arterial bleeding can result in severe internal bleeding. External arterial bleeding is bright red (because it is oxygenated), and it spurts from the wound because of the heart’s pumping action.
Types of Wounds
Wounds are injuries that involve soft-tissue damage and, often, blood loss. Wounds can be open or closed, major or minor, and superficial or deep.
Open wounds are soft-tissue injuries that involve a break in the skin. These wounds can be as minor as a small scrape of the surface layer of the skin or as severe as a large, deep cut or torn-away body part. The 6 main types of open wounds are:
- Abrasion - The rubbing or scraping away of skin
- Amputation - The removal of a body part by injury, prolonged constriction, or surgery
- Avulsion – The tearing away of the skin
- Ballistic injury – The piercing and destruction of body tissue caused by the discharge of firearms or munitions
- Crush injury – The pressing, squeezing, or smashing of a body part by a heavy object or force
- Incision – The precise cutting made by a scalpel or similar instrument
- Laceration – The cutting or splitting of the skin
- Puncture/penetration – The piercing of the skin by a sharp, pointed object, which may or may not remain embedded in the wound
Closed wounds occur beneath the skin. As with external bleeding, internal bleeding can be minor or severe. For example:
- Bruising. A minor closed wound usually involves small blood vessels near the surface of the skin and results in a black-and-blue mark called a bruise. The medical term for a bruise is a contusion or ecchymosis. A small bruise actually changes color (from red to black and blue to greenish-brown to yellowish-brown) as the body breaks down the blood and reabsorbed it.
- Hematoma. A hematoma (a collection of partially clotted blood) occurs when larger vessels are broken, causing more blood to escape deeper into body tissue. Although they may look like a bruise, hematomas are often hard, swollen, and very painful. Sometimes your physician may recommend draining the blood from the tissue to help the body heal. In particular, intracranial hematomas may require an operation to prevent pressure on the brain, severe headaches, coma, etc.
- Internal bleeding. Internal bleeding occurs when large arteries or veins are severed. This usually results from a fall, a severe head injury, blunt trauma to the body, or any injury with broken bones that puncture organs or blood vessels. Rapid bleeding called hemorrhaging causes blood to flow into tissue and body cavities. Uncontrolled hemorrhaging is a life-threatening condition that can quickly result in organ failure, severe shock, and death.
General Care Steps
The general care steps for bleeding vary for internal and external bleeding and for minor and severe bleeding.
Minor internal bleeding
Bruises often resolve themselves in a few days time. Use RICE to prevent further injury and to reduce pain and swelling:
- Rest the area
- Apply Ice
- Compress the injury site with a bandage
- Elevate the area if this does not cause further pain
If the injury site maintains hard, swollen, and discolored for several days, it may be a hematoma. The blood may need to be extracted from the tissue to prevent infection and to speed healing. This should only be attempted by a physician. When in doubt about the severity of internal bleeding, call for emergency personnel.
Severe internal bleeding
You should suspect internal bleeding when there is severe trauma as well as signs of paleness, bruising, sweating, weakness, and thirst. To care for suspected severe internal bleeding:
- Call emergency personnel
- Monitor the patient and be ready to respond to any life-threatening conditions
- Stop any external bleeding (sometimes in trauma cases, there is both internal and external bleeding)
- Care for shock by keeping the patient still, maintaining normal body temperature, reassuring the patient, and not giving anything to eat or drink
- If the wound is in the trunk of the body (i.e., the ventral cavity) and local protocols allow, apply a wound stasis treatment like DARPA Foam (although not FDA approved, the developers of this foam are seeking this approval for both military and civilian uses)
Minor external bleeding
For minor cuts, scrapes, and puncture wounds:
- Clean the wound with running water (i.e., irrigate the wound)
- Dry the area with a sterile gauze pad
- Cover the wound with a sterile dressing and bandage
- Apply direct pressure, if necessary
- Monitor the patient for any sign of infection or shock
Many local protocols will not allow you to apply soaps, antibiotic creams/ointments, or anesthetics due to the risk of an allergic reaction. Irrigation with clean water alone does an adequate job of cleansing a superficial wound.
Severe external bleeding
You must control wounds with spurting or fast-flowing blood. Do not take time to clean a severely bleeding wound because by doing may increase bleeding and shock. Watch a video about controlling bleeding by The Doctors.
To care for severe bleeding:
- Call emergency personnel
- Control bleeding by:
- Applying direct pressure with a gauze pad or clean cloth directly over the wound (see exceptions below)
- Securing the dressing in place with a pressure bandage as explained in the following videos or on the Bandaging page
- Re-establishing and maintaining direct pressure for several minutes until bleeding stops
- If blood soaks through the bandages:
- Apply additional bandaging
- Reapply direct pressure over the bandages and maintain for several minutes
- Care for shock by:
- Keeping the patient still
- Maintaining normal body temperature
- Comforting and reassuring the patient
(It is no longer recommended to use elevation and pressure points to control bleeding. These techniques, while they may contribute to bleeding control, are often applied without maintaining direct pressure, the most effective way to control external bleeding. If you apply either technique, ALWAYS maintain direct pressure while doing so!)
DO NOT APPLY DIRECT PRESSURE for the following:
- Skull fractures – Apply pressure to the area around the fracture
- Eyeball bleeding/dislocation – Do not cover the injured eye or touch the eyeball with anything
- Eviscerations – Apply a large, moistened trauma dressing directly on the wound, cover with plastic wrap, and then cover with a blanket/towel; do not apply pressure or try to push protruding organs back into the body
- Open fractures – Apply pressure and bandage around the protruding bone; do not try to push the bone back under the skin
- Embedded objects – Apply pressure around the embedded object; use bulky dressings and bandages to support the object in place; and do not remove the object unless it is interfering with CPR or giving ventilations.
Other methods to control external bleeding
Other measures to control severe external bleeding include hemostatic agents and tourniquets. These measures are more appropriate in situations where emergency medical care and hospitalization are delayed and/or direct pressure and bandaging is ineffective in controlling blood loss.
- Hemostatic agents use chemicals to constrict tissue or remove moisture from blood to hasten clot formation.
- Tourniquets are commercial or improvised devices that constrict blood vessels on an arm or leg to the point that bleeding stops. Because of the likelihood of permanent tissue damage, a tourniquet should only be applied as a last resort to save the patient’s life. Once you apply a tourniquet in a prehospital setting, do not remove it. Record the time you applied the tourniquet, and give this information to more advanced medical personnel.