A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is benign and is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood vessels. An ecchymosis is a hematoma of the skin larger than 10 mm. They may occur among and or within many areas such as skin and other organs, connective tissues, bone, joints and muscle. A collection of blood (or even a hemorrhage) may be aggravated by anticoagulant medication (blood thinner). Blood seepage and collection of blood may occur if heparin is given via an intramuscular route; to avoid this, heparin must be given intravenously or

subcutaneously The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and ma ...

Signs and symptoms

Some hematomas are visible under the surface of the skin (commonly called bruises) or possibly felt as masses or lumps. Lumps may be caused by the limitation of the blood to a sac,

subcutaneous Subcutaneous may refer to: * Subcutaneous injection * Subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The ...

or intramuscular tissue space isolated by fascial planes. This is a key anatomical feature that helps prevent injuries from causing massive blood loss. In most cases a hematoma as a sac of blood eventually dissolves; however, in some cases it may continue to grow due to blood seepage or show no change. If the sac of blood does not disappear, then it may need to be surgically cleaned out or repaired. The slow process of reabsorption of hematomas can allow the broken down blood cells and hemoglobin pigment to move in the connective tissue. For example, a patient who injures the base of their thumb might cause a hematoma, which will slowly move all through their finger within a week. Gravity is the main determinant of this process. Hematomas on articulations can reduce mobility of a member and present roughly the same symptoms as a fracture. In most cases, movement and exercise of the affected muscle is the best way to introduce the collection back into the bloodstream. A misdiagnosis of a hematoma in the vertebra can sometimes occur; this is correctly called a hemangioma (buildup of cells) or a benign tumor.

Classification

Types

* Subdermal hematoma (under the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

) * Intramuscular hematoma (inside muscle tissue) * Skull/brain: ** Subgaleal hematoma – between the galea aponeurosis and periosteum ** Cephalohematoma – between the periosteum and

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

. Commonly caused by vacuum delivery and vertex delivery. ** Epidural hematoma – between the

and

dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous syste ...

** Subdural hematoma – between the

and arachnoid mater ** Subarachnoid hematoma – between the arachnoid mater and pia mater (the subarachnoid space) ** Othematoma – between the skin and the layers of cartilage of the ear * Breast hematoma (

breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and s ...

) * Perichondral hematoma ( ear) * Perianal hematoma ( anus) * Subungual hematoma (nail) * Rectus sheath hematoma

Degrees

* Petechiae – small pinpoint hematomas less than 3 mm in diameter * Purpura (purple) – a bruise about 3 – 5 mm in diameter, generally round in shape * Ecchymosis – subcutaneous extravasation of blood in a thin layer under the skin, i.e. bruising or "black and blue," over 1 cm in diameter

Etymology

The English word "hematoma" came into use in 1826. The word derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

αἷμα ''haima'' "blood" and -ωμα ''-oma'', a suffix forming nouns indicating a mass or tumor."hematoma"
'' Online Etymology Dictionary.''

References

External links

* {{Authority control Gross pathology