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 Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where t ...

medication (blood thinner). Blood seepage and collection of blood may occur if

heparin Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treat ...

is given via an

intramuscular Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles ha ...

route; to avoid this, heparin must be given intravenously or subcutaneously.

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 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 In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

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 Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displ ...

. 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 animal coverings, such as the arthropod exoskeleton, have different ...

) * Intramuscular hematoma (inside muscle tissue) * Skull/brain: ** Subgaleal hematoma – between the

galea aponeurosis The epicranial aponeurosis (aponeurosis epicranialis, galea aponeurotica) is an aponeurosis (a tough layer of dense fibrous tissue). It covers the upper part of the skull in humans and many other animals. Structure In humans, the epicrania ...

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, th ...

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

and dura mater ** Subdural hematoma – between the dura mater 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 sec ...

) * Perichondral hematoma ( ear) * Perianal hematoma (

anus The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, ...

) * Subungual hematoma (nail) * Rectus sheath hematoma

Degrees

Petechiae A petechia () is a small red or purple spot (≤4 mm in diameter) that can appear on the skin, conjunctiva, retina, and mucous membranes which is caused by haemorrhage of capillaries. The word is derived from Italian , 'freckle,' of obscure origi ...

– small pinpoint hematomas less than 3 mm in diameter *

Purpura Purpura () is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, ...

(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 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