The key difference between hemorrhage and hematoma is that hemorrhage is defined as the leaking of blood from a blood vessel due to lack of integrity in the vessel wall or clotting mechanism whereas hematoma is defined as the accumulation of leaked blood inside the body within tissue planes.
What is Hemorrhage?
In a normal person, blood is circulated within a closed system of vessels consisting of arteries, veins, and capillaries. The velocity of the blood flow is greater in larger vessels. Causes of bleeding can vary from collagen defects to trauma. When there is damage to large vessels, bleeding will be more severe. There are mechanisms to stop bleeding after an injury to the vessels wall. Examples of such mechanisms are clot formation, contraction of the vessel wall at the site of injury. Failure of these mechanisms can lead to persistent bleeding even after a small injury. In a bleeding, blood may be leaked outside the body or into the body cavities such as peritoneum and pleural cavity.
Severe persistent bleeds can lead to hemodynamic compromise and death unless the person is not resuscitated properly. Initial signs of a bleeding are faintishness, increase in pulse rate, pale look, etc. It is important to stop bleeding as soon as possible. Methodology to stop bleeding depends on the site, severity and the cause of the bleed. Sometimes systemic causes such as loss of clotting factors can lead to a bleeding tendency in apparently normal blood vessels. Liver disease and hemophilia are examples for such situations. Examples for methodology to stop bleeding are applying pressure at the site of bleeding, medicines such as fibrinolytic, clotting factor replacement or even surgery to ligate leaking blood vessels.
What is Hematoma?
Hematoma is an internal accumulation of blood within tissue planes. Expansion of the blood clot will be limited by the pressure from the surrounding tissues. Hematoma can be of different sizes, depending on several factors. If the bleeding occurs around a lax tissue plane hematoma will expand easily and will be larger. Periorbital hematoma is an example for this. Tense tissue planes will have more resistance to the expansion of the blood clot. Retroperitoneal hematoma is an example for this where peritoneum exerts some resistance. This effect is called tamponade effect.
Intervention for hematoma depends on the site and the size of the hematoma. Small hematoma in a site with high surgical risk with can be managed conservatively whereas a larger expanding hematoma need immediate surgical exploration, evacuation of the clot and hemostasis to prevent re-accumulation. Hematomas can lead to additional complications such as infection of the clot.
Diagram of the infant scalp showing the locations of the common hematomata of the scalp in relation the layers of the scalp.
What is the difference between Hemorrhage and Hematoma?
Definition of Hemorrhage and Hematoma:
Hemorrhage: Leakage of blood outside the blood vessel is considered as hemorrhage.
Hematoma: Accumulation of blood within tissue planes is considered as hematoma formation.
Features of Hemorrhage and Hematoma:
Mechanism of cessation of bleeding:
Hemorrhage: While bleeding, tissue resistance has no effect.
Hematoma: In hematoma, tissue resistance has some effect on preventing further expansion of the blood clot.
Location:
Hemorrhage: Bleeding can occur from any blood vessel and could occur even outside the body or into body cavities.
Hematoma: Hematoma always occurs inside the body and occurs only in relation to certain sites which are favorable for hematoma formation.
Management:
Hemorrhage: Bleeding may need surgical ligation of the blood vessel in a severe bleed.
Hematoma: Hematoma may need surgical evacuation of the hematoma other than ligation of the responsible vessel.
Other Complications:
Hemorrhage: Chronic bleeding can lead to anemia.
Hematoma: Hematoma can cause jaundice and infection of the clot in same cases.
Image Courtesy:
“Stroke hemorrhagic” by National Heart Lung and Blood Insitute (NIH) – National Heart Lung and Blood Insitute (NIH). (Public Domain) via Commons
“Scalp hematomas” by AMH Sheikh – Own work. (CC BY-SA 3.0) via Commons