A bruise, also known as a contusion, is a type of
hematoma of
tissue, the most common cause being
capillaries damaged by
trauma, causing localized bleeding that
extravasates into the surrounding
interstitial tissues. Most bruises occur close enough to the
epidermis such that the bleeding causes a visible discoloration. The bruise then remains visible until the blood is either absorbed by tissues or cleared by
immune system action. Bruises which do not
blanch under pressure can involve capillaries at the level of skin,
subcutaneous tissue
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, or 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 ...
, muscle, or bone.
Bruises are not to be confused with other similar-looking
lesions. Such lesions include
petechia (less than , resulting from numerous and diverse etiologies such as adverse reactions from medications such as warfarin, straining, asphyxiation,
platelet
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
disorders and diseases such as ''
cytomegalovirus''); and
purpura (), classified as palpable purpura or non-palpable purpura and indicating various pathologic conditions such as
thrombocytopenia. Additionally, although many
terminology
Terminology is a group of specialized words and respective meanings in a particular field, and also the study of such terms and their use; the latter meaning is also known as terminology science. A ''term'' is a word, Compound (linguistics), com ...
schemas treat an ecchymosis (plural, ecchymoses) (over ) as synonymous with a bruise,
in some other schemas, an ecchymosis is differentiated by its remoteness from the source and cause of bleeding, with blood dissecting through tissue planes and settling in an area remote from the site of trauma or even nontraumatic pathology, such as in
periorbital ecchymosis ("
raccoon eyes"), arising from a
basilar skull fracture or from a
neuroblastoma.
As a type of hematoma, a bruise is always caused by internal bleeding into the interstitial tissues which does not break through the skin, usually initiated by
blunt trauma, which causes damage through
physical compression and
deceleration forces. Trauma sufficient to cause bruising can occur from a wide variety of situations including accidents, falls, and surgeries. Disease states such as insufficient or malfunctioning
platelet
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
s, other
coagulation deficiencies, or vascular disorders, such as venous blockage associated with severe
allergies
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...
can lead to the formation of purpura which is not to be confused with trauma-related bruising/contusion. If the trauma is sufficient to break the skin and allow blood to escape the interstitial tissues, the injury is not a bruise but bleeding, a different variety of hemorrhage. Such injuries may be accompanied by bruising elsewhere.
[
Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007). ''Robbins Basic Pathology'' (8th ed.). Saunders Elsevier. p. 86 ]
Signs and symptoms
Bruises often induce pain immediately after the trauma that results in their formation, but small bruises are not normally dangerous alone. Sometimes bruises can be serious, leading to other more life-threatening forms of hematoma, such as when associated with serious injuries, including
fractures and more severe
internal bleeding. The likelihood and severity of bruising depends on many factors, including type and healthiness of affected tissues. Minor bruises may be easily recognized in people with light skin color by characteristic blue or purple appearance (idiomatically described as "black and blue") in the days following the injury.
Hematomas can be subdivided by size. By definition, ecchymoses are 1 centimetres in size or larger, and are therefore larger than
petechiae (less than 3 millimetres in diameter)
or
purpura (3 to 10 millimetres in diameter). Ecchymoses also have a more diffuse border than other purpura.
A broader definition of ecchymosis is the escape of blood into the tissues from ruptured blood vessels. The term also applies to the subcutaneous discoloration resulting from seepage of blood within the injured tissue.
Bruise colors vary from red, blue, or almost black, depending on the severity of broken capillaries or blood vessels within the bruise site. Broken
venules or
arterioles often result in a deep blue or dark red bruise, respectively. Darker colored bruises may result from a more severe bleeding from both blood vessels. Older bruises may appear yellow, green or brown.
Cause
There are many causes of subcutaneous hematomas including ecchymoses.
Coagulopathies such as
hemophilia A may cause ecchymosis formation in children.
The medication
betamethasone can have the adverse effect of causing ecchymosis.
The presence of bruises may be seen in patients with
platelet
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
or
coagulation disorders, or those who are being treated with an
anticoagulant. Unexplained bruising may be a warning sign of
child abuse or
domestic abuse, hard blows in
fighting sports, shot by
rubber bullets during
protests, hit by fallen objects/trapped inside debris during
earthquake
An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...
s and/or serious medical problems such as
leukemia or
meningoccocal infection. Unexplained bruising can also indicate internal bleeding or certain types of cancer. Long-term glucocorticoid therapy can cause easy bruising. Bruising present around the
navel
The navel (clinically known as the umbilicus; : umbilici or umbilicuses; also known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord.
Structure
The u ...
(belly button) with severe abdominal pain suggests acute
pancreatitis. Connective tissue disorders such as
Ehlers–Danlos syndrome may cause relatively easy or spontaneous bruising depending on the severity. Spontaneous bruising or bruising with minimal trauma in the absence of other explanations and together with other minor or major criteria suggestive of vascular Ehlers–Danlos Syndrome (vEDS) suggests
genetic testing for the condition.
During an
autopsy, bruises accompanying
abrasions indicate the abrasions occurred while the individual was alive, as opposed to damage incurred post mortem.
Size and shape
Bruise shapes may correspond directly to the instrument of injury or be modified by additional factors. Bruises often become more prominent as time lapses, resulting in additional size and swelling, and may grow to a large size over the course of the hours after the injury that caused the bruise was inflicted.
* Condition and type of tissue: In soft tissues, a larger area is bruised than would be in firmer tissue due to ease of blood to invade tissue.
* Age: elderly skin and other tissues are often thinner and less elastic and thus more prone to bruising.
* Gender: More bruising occurs in females due to increased
subcutaneous fat.
* Skin tone: Discoloration caused by bruises is more prominent in lighter complexions.
* Diseases:
Coagulation,
platelet
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
and blood vessel diseases or deficiencies can increase bruising due to more bleeding.
* Location: More extensive vascularity causes more bleeding. Areas such as the arms, knees, shins and the facial area are especially common bruise sites.
* Forces: Greater striking forces cause greater bruising.
* Genes: Despite having completely normal coagulation factors, natural
redheads have been shown to bruise more, although this may just be due to greater visibility on commonly associated lighter complexion.
Severity
Bruises can be scored on a scale from 0–5 to categorize the severity and danger of the injury.
The harm score is determined by the extent and severity of the injuries to the organs and tissues causing the bruising, in turn depending on multiple factors. For example, a
contracted muscle will bruise more severely, as will tissues crushed against underlying bone.
Capillaries vary in strength, stiffness and toughness, which can also vary by age and medical conditions.
Low levels of damaging forces produce small bruises and generally cause the individual to feel minor pain straight away. Repeated impacts worsen bruises, increasing the harm level. Normally, light bruises heal nearly completely within two weeks, although duration is affected by variation in severity and individual healing processes; generally, more severe or deeper bruises take somewhat longer.
Severe bruising (harm score 2–3) may be dangerous or cause serious complications. Further bleeding and excess fluid may accumulate causing a hard, fluctuating lump or swelling hematoma. This has the potential to cause
compartment syndrome in which the swelling cuts off blood flow to the tissues. The trauma that induced the bruise may also have caused other severe and potentially fatal harm to internal
organs. For example, impacts to the head can cause
traumatic brain injury: bleeding, bruising and massive swelling of the brain with the potential to cause
concussion,
coma and death. Treatment for brain bruising may involve emergency surgery to relieve the pressure on the brain.
Damage that causes bruising can also cause bones to be
broken,
tendon
A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
s or muscles to be
strained,
ligaments to be
sprained, or other tissue to be damaged. The symptoms and signs of these injuries may initially appear to be those of simple bruising. Abdominal bruising or severe injuries that cause difficulty in moving a limb or the feeling of liquid under the skin may indicate life-threatening injury and require the attention of a physician.
Mechanism

Increased distress to tissue causes
capillaries to break under the skin, allowing blood to escape and build up. As time progresses, blood seeps into the surrounding tissues, causing the bruise to darken and spread.
Nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...
endings within the affected tissue detect the increased pressure, which, depending on severity and location, may be perceived as pain or pressure or be
asymptomatic. The damaged capillary
endothelium releases
endothelin, a
hormone
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...
that causes
narrowing of the blood vessel to minimize bleeding. As the endothelium is destroyed, the underlying
von Willebrand factor is exposed and initiates
coagulation, which creates a temporary
clot to plug the wound and eventually leads to restoration of normal tissue.
During this time, larger bruises may change color due to the breakdown of
hemoglobin from within escaped
red blood cells in the extracellular space. The striking colors of a bruise are caused by the
phagocytosis
Phagocytosis () is the process by which a cell (biology), cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs ph ...
and sequential degradation of hemoglobin to
biliverdin to
bilirubin to
hemosiderin, with hemoglobin itself producing a red-blue color, biliverdin producing a green color, bilirubin producing a yellow color, and hemosiderin producing a golden-brown color.
As these products are cleared from the area, the bruise disappears. Often the underlying tissue damage has been repaired long before this process is complete.
Treatment

Treatment for light bruises is minimal and may include
RICE
Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...
(
rest,
ice
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...
,
compression, and
elevation
The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
),
painkillers (particularly
NSAIDs) and, later in recovery, light stretching exercises. Particularly, immediate application of ice while elevating the area may reduce or completely prevent swelling by restricting blood flow to the area and preventing internal bleeding. Rest and preventing re-injury is essential for rapid recovery.
Very gently massaging the area and applying heat may encourage blood flow and relieve pain according to the
Gate control theory of pain, although causing additional pain may indicate the massage is exacerbating the injury. As for most injuries, these techniques should not be applied until at least three days following the initial damage to ensure all internal bleeding has stopped, because although increasing blood flow will allow more healing factors into the area and encourage drainage, if the injury is still bleeding this will allow more blood to seep out of the wound and cause the bruise to become worse.
History
Folk medicine, including ancient medicine of Egyptians, Greeks, Celts, Turks, Slavs, Maya, Aztecs and Chinese, has used bruising as a treatment for some health problems. The methods vary widely and include cupping, scraping, and slapping.
Fire cupping uses suction which causes bruising in patients. Scraping (
gua sha) uses a small hand device with a rounded edge to gently scrape the scalp or the skin. Another ancient device that creates mild bruising is a
strigil, used by Greeks and Romans in the bath. Archaeologically there is no precedent for scraping tools before Greek archaeological evidence, not Chinese or Egyptian.
[Kotera-Fayer "Die Strigilis" 93]
Etymology and pronunciation
The word ''ecchymosis'' (; plural ''ecchymoses'', ), comes to English from
Neo-Latin
Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...
, based on
Greek , from , from (elided to ) and .
Compare ''enchyma'', "tissue infused with organic juice"; elaboration from chyme, the formative juice of tissues.
See also
*
Blunt trauma
*
Black eye
*
Blister
*
Burn
*
Cerebral contusion – bruising of
brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...
tissue
*
Kissing contusion – contusions of both surfaces of the knee joint
*
Love-bite – bruising created by excessive
suction of a particular area of skin, associated with an individual kissing or sucking the affected area beforehand
*
Myocardial contusion – bruising of the
heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...
muscle
*
Pulmonary contusion – bruising of
lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...
tissue
*
Ship foota bruise underneath the
toenail
*
Subconjunctival hemorrhage
*
Welts
References
External links
What is a bruise?for kids
Bruises in sports
{{Authority control
Dermatologic terminology
Hematology
Injuries
Medical signs