Definition & Overview

Bleeding is defined as the loss of blood. The organs and blood vessels contain blood. If any of these is damaged, blood can flow freely inside or outside the body. If blood flows inside the body, it’s referred to as internal bleeding. If it flows through a break in the skin or a natural body opening, such as the vagina, rectum, mouth, nose, or ears, it’s called external bleeding.

Internal and external bleeding can be caused by a wide variety of factors, such as diseases and injuries. Bleeding can occur anywhere within the body. However, the body has its own sophisticated method of preventing too much loss of blood called hemostasis. When the body detects blood flowing from a ruptured blood vessel, it coagulates (clots) the blood to block the lesion and prevent more from flowing through. The healing process then follows.

However, if the wound is severe, there won’t be enough time for blood clots to form. If the body loses too much blood, organs will begin to fail and death will naturally follow.

Cause of Condition

Injuries and diseases are the primary causes of bleeding. Injuries to any part of the body may cause a blood vessel to rupture, even without the skin being pierced. A good example is a bruise caused by a heavy blow. A bruise is initially red in color due to the collection of blood released from ruptured capillaries. This type of bleeding is usually minor in nature and often does not require medical intervention.

However, if the blow causes a lesion in the skin, it will cause external bleeding. Blood clots are usually able to prevent blood from flowing through small lesions. If the lesion is large enough, clotting will not be able to stop the blood from flowing and the wound will need to be closed using sutures.

A wide variety of disease cause bleeding. Some of the most common are leukemia, lung cancer, acute bronchitis, and liver disease. Medications, such as blood thinners may also cause bleeding.

Menstruation is another cause of bleeding, but this type of bleeding is a natural process in women. It occurs when a woman discharges blood from the lining of the uterus. However, in some cases, bleeding may be excessive during menstruation or may occur between menstrual cycles. Cervical polyps or other medical conditions can cause excessive bleeding.

Bleeding may also be caused by threatened abortion, otherwise known as a miscarriage. A miscarriage occurs during the first 20 weeks of pregnancy. If the pregnancy progresses to full term, but the baby is lost, it is referred to as a stillbirth.

Key Symptoms

The primary symptom of bleeding is the loss of blood either through an external or internal wound. If the bleeding is not stopped, the patient may go into shock. In some cases, fever or infection may also develop.

Who to See & Types of Treatment Available

It’s imperative that bleeding is stopped as soon as possible to prevent excessive blood loss. As much as possible, the patient should receive immediate medical treatment. However, if a medical professional is not on site, a person trained in first-aid techniques should attempt to stop the bleeding.

A patient with an external wound that is bleeding profusely will normally be a bit agitated. It’s important to calm the person first to prevent the heart from pumping too much and causing pressure. If a large object is stuck in the wound, it should not be removed. Loose dirt can be removed carefully.

The next step is to cover the wound with a clean cloth (if possible) and apply pressure. Adhesive tape or a strip of cloth can also be used to maintain the pressure. If blood seeps through the clean cloth, maintain the pressure. It’s important not to release pressure or remove the cloth at this point.

Tourniquets may also be used, but should only be applied by a trained person. Otherwise, continue applying pressure until emergency medical services arrive. When the patient reaches the hospital, doctors will surgically remove any large objects lodged in the wound and close the wound using sutures.

If bleeding is through a natural opening in the body, such as the nose, vagina, mouth, or ears, it means that an internal wound has occurred. Such wound can be caused by a wide variety of factors. It’s imperative that the patient be brought to a hospital’s emergency department immediately so that the condition can be diagnosed and the bleeding stopped.

Bleeding, whether internal or external, can result in death. If a person loses a half or a third of the body’s blood supply, the possibility of death is extremely high. It’s important to remember that a person may bleed to death even if blood isn’t visible. A catastrophic internal hemorrhage can cause excessive blood loss that might not leak out of the body immediately.


  • Cornwell EE. Initial approach to trauma. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004: chap 251.

  • Lammers, RL. Principles of Wound Management. In: Roberts JR, Hedges JR eds. Roberts: Clinical Procedures in Emergency Medicine. 5th ed.Philadelphia, Pa. Saunders Elsevier; 2009: chap 39.

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