A scalp hematoma is a collection of blood that pools between the layers of tissue covering the skull, usually after a blow or bump to the head. Most are minor, producing a tender swelling that resolves on its own within a couple of weeks. But depending on exactly which tissue layer the blood collects in, a scalp hematoma can range from a harmless “goose egg” to a life-threatening emergency in newborns. Understanding the differences matters because the layer involved determines how the swelling behaves, what complications can follow, and whether you need medical attention at all.
Why the Scalp Bleeds So Easily
The scalp is one of the most blood-rich areas of the body. It is organized in several distinct layers stacked on top of the skull bone: skin, a dense connective-tissue layer, a thin muscular sheet called the galea aponeurotica, a loose connective-tissue space beneath the galea, and finally the periosteum that clings directly to bone. Each of these layers has its own blood supply, and the vessels in the outermost layers are held open by the surrounding connective tissue. That is why even a small scalp cut can bleed dramatically.
When blunt force hits the head, blood vessels in one or more of these layers can rupture without breaking the skin. The blood leaks out and pools, forming a hematoma. Where exactly it pools depends on the force, direction, and location of the impact. The three main types of scalp hematoma are classified by which layer the blood ends up in, and each type behaves differently.
Three Types, Three Behaviors
The most common and least dangerous type is a subcutaneous hematoma, the everyday “goose egg.” Blood collects in the dense tissue just beneath the skin. Because this layer is tightly bound by connective-tissue fibers, the swelling stays localized to a firm, raised lump right at the site of impact. After a blunt head injury, this kind of lump usually appears almost immediately and then gradually shrinks and heals without any treatment.1PubMed Central. Identity of growing pulsatile mass lesion of the scalp after blunt head injury: Case reports and literature review
A subgaleal hematoma is more serious. Here, blood collects in the loose tissue space beneath the galea aponeurotica. Because this space has almost no internal structure to contain the bleeding, blood can spread freely across the entire scalp, crossing over skull suture lines. In newborns, up to 250 to 300 milliliters of blood can accumulate in this space, which is a staggering volume for an infant whose total blood supply may be only slightly more than that. Large subgaleal hemorrhages can cause dangerous drops in blood pressure, clotting problems, and hemorrhagic shock.2Current Pediatrics. Neonatal Subgaleal Hemorrhage: Narrative Review
A cephalohematoma (sometimes spelled cephalhematoma) sits beneath the periosteum, the membrane attached to the outer surface of the skull bone. Because the periosteum is firmly attached at the edges of each skull bone, blood in this layer cannot cross suture lines. That means a cephalohematoma stays confined to one bone, usually one of the parietal bones at the top of the head. This type is almost exclusively seen in newborns after difficult deliveries.
Causes in Adults
In adults and older children, the overwhelming majority of scalp hematomas result from direct blunt trauma: falls, car accidents, sports collisions, walking into a cabinet, or any impact to the head. Most of these produce subcutaneous hematomas that look and feel like a firm, tender bump. They peak in size over the first day or two, then slowly fade through the familiar green-and-yellow bruising stages over one to three weeks.
Occasionally, though, a blunt injury can damage a scalp artery in a way that does not become obvious right away. Instead of a simple lump that shrinks, the swelling grows and may feel pulsatile, like a heartbeat under the skin. This can signal a pseudoaneurysm or an abnormal connection between an artery and a vein, both of which require medical evaluation because they will not heal on their own.1PubMed Central. Identity of growing pulsatile mass lesion of the scalp after blunt head injury: Case reports and literature review
Blood-thinning medications are another important factor. People taking anticoagulants face a significantly higher risk of bleeding complications after head trauma. Anticoagulation at standard therapeutic levels raises the risk of intracranial hemorrhage roughly seven- to tenfold, and the danger increases further with advanced age, high blood pressure, or a history of stroke.3Stroke. Oral anticoagulants and intracranial hemorrhage. Facts and hypotheses While that statistic refers to bleeding inside the skull rather than on top of it, the same anticoagulant effect makes scalp hematomas larger, slower to resolve, and more likely to need medical follow-up.
Causes in Newborns
Scalp hematomas are common in newborns, particularly after complicated deliveries. The forces involved in passing through the birth canal can rupture blood vessels in the scalp, and the risk jumps sharply when instruments are used to assist delivery. Vacuum extraction carries a substantially higher risk of cephalohematoma compared with unassisted vaginal delivery.4PubMed Central. Maternal and Neonatal Complications Resulting From Vacuum-Assisted and Normal Vaginal Deliveries In rare cases, vacuum extraction can also cause a skull fracture complicated by both subgaleal and subdural hemorrhage, a much more dangerous combination.5PubMed Central. A parietal bone fracture with subgaleal and subdural hemorrhage in association with vacuum extraction delivery
Most neonatal cephalohematomas are benign and resolve on their own over several weeks. Caput succedaneum, the diffuse soft swelling of the scalp that many babies have immediately after birth, is even more benign. It is caused by pressure during delivery and typically disappears within a day or two. The key difference is that caput crosses suture lines because it sits in the superficial tissue layers, while a cephalohematoma does not.
Subgaleal hematomas in newborns are the rarest of the three types but the most dangerous, precisely because of the unrestricted space available for blood to accumulate. These require urgent monitoring and sometimes transfusion. A baby with a subgaleal hemorrhage may show a fluctuating, boggy swelling that seems to spread across the head rather than staying in one spot, along with signs of dropping blood volume like pallor, rapid heart rate, and poor feeding.2Current Pediatrics. Neonatal Subgaleal Hemorrhage: Narrative Review
Symptoms and Warning Signs
The most obvious symptom of any scalp hematoma is a visible or palpable lump at the site of injury. Pain and tenderness are typical, and you may notice discoloration of the overlying skin that spreads and changes color over the following days. A subcutaneous hematoma feels firm and localized, while a subgaleal collection feels softer and can shift or spread when pressed.
The swelling alone is not usually the main concern. What matters most is whether the force that caused the scalp hematoma also injured the brain or skull underneath. Warning signs that suggest something more than a simple bump include:
- Persistent headache: pain that worsens over hours rather than gradually improving
- Confusion or drowsiness: difficulty staying awake, slurred speech, or disorientation
- Vomiting: especially repeated vomiting after the initial injury
- Unequal pupils: one pupil larger than the other
- Seizures: any convulsive activity after head trauma
- Clear fluid from the nose or ear: which may indicate a skull base fracture
Any of those symptoms warrant emergency evaluation. In infants, watch for a bulging fontanelle (the soft spot), inconsolable crying, refusal to feed, or unusual lethargy.
When Imaging Is Needed
Not every scalp hematoma needs a CT scan, but a scalp hematoma in a young child does raise the question of whether a skull fracture lurks underneath. In one study of children under six who presented to an emergency department with a scalp hematoma after minor head trauma, roughly eight percent had an underlying skull fracture detected on CT.6PubMed Central. Point-of-care ultrasound diagnosis of skull fracture in Chinese children 0–6 years old with scalp hematoma from minor head trauma: A preliminary prospective observational study That is a high enough rate that clinicians take scalp hematomas in young children seriously, even when the child appears well.
Point-of-care ultrasound is emerging as a useful screening tool in this setting. In that same study, bedside ultrasound showed strong agreement with CT for detecting skull fractures, with high sensitivity and specificity.6PubMed Central. Point-of-care ultrasound diagnosis of skull fracture in Chinese children 0–6 years old with scalp hematoma from minor head trauma: A preliminary prospective observational study Because ultrasound involves no radiation, it is an attractive first step, especially for children who might otherwise get an unnecessary CT scan. However, CT remains the standard when intracranial bleeding is suspected, since ultrasound cannot see through the skull to evaluate the brain itself.
In adults, imaging decisions follow established clinical guidelines for head trauma. A simple goose egg in someone who is fully alert and has no other symptoms typically does not need a scan. The decision changes when the person is on blood thinners, is over 65, lost consciousness, has worsening symptoms, or experienced a high-energy mechanism like a car crash.
Treatment of Uncomplicated Scalp Hematomas
The good news is that most scalp hematomas need nothing more than basic first-aid measures. For a standard subcutaneous hematoma, cold compresses applied intermittently during the first 24 to 48 hours help limit swelling. Over-the-counter pain relievers can manage discomfort, though you should avoid aspirin and ibuprofen in the acute phase if there is any concern about ongoing bleeding, since they impair clotting. Rest and monitoring are usually sufficient. The lump softens over a week or two and eventually disappears.
For neonatal cephalohematomas, the standard approach is observation. Pediatricians typically advise against needle aspiration of a cephalohematoma because the risk of introducing infection into a closed blood collection outweighs the benefit of draining it. Most cephalohematomas reabsorb on their own within a few weeks to a few months.
When Drainage or Surgery Becomes Necessary
Surgical intervention comes into play when a scalp hematoma is very large, expanding, infected, or causing complications like significant blood loss. In subgaleal hematomas, drainage may be necessary when the volume of trapped blood is large enough to cause hemodynamic instability, but the decision is not taken lightly. Drainage carries its own risk: removing the blood can disrupt the tamponade effect of surrounding tissues, potentially leading to additional hemorrhage into the subgaleal space.7Pediatric Neurosurgery. Infected Subgaleal Hematoma Following Blunt Head Trauma in a Child: Case Report and Review of the Literature There is also a risk of iatrogenic infection, because the emissary veins in this region connect to the venous sinuses inside the skull, creating a potential pathway for bacteria to reach the brain.8PubMed Central. Traumatic subgaleal hematoma drainage in an adolescent: a case report and review of the literature
When drainage is performed, needle aspiration is usually the initial step, and the fluid is sent for laboratory analysis to check for infection. Depending on the findings, formal surgical drainage may follow. The goal is to balance the benefit of removing a large or problematic blood collection against the risks of disturbing the body’s natural containment of the bleed.
Infection as a Complication
Scalp hematomas occasionally become infected, and when they do, things can escalate quickly. A blood collection is an excellent growth medium for bacteria. Infection can turn a cephalohematoma into a deep-seated scalp abscess, and in severe cases the infection can spread to the underlying bone, causing osteomyelitis, or even reach the meninges and bloodstream. One case report described a newborn whose cephalohematoma became infected with Escherichia coli, resulting in a large abscess, skull osteomyelitis, meningitis, and E. coli septicemia.9PubMed. Cephalhematoma infected by Escherichia coli presenting as an extensive scalp abscess
Recognizing infection early is critical. Warning signs include increasing redness, warmth, and swelling over the hematoma; fever; and a change in the consistency of the lump from firm or fluctuant to increasingly tense and tender. Prompt antibiotic treatment can prevent the progression to abscess formation and osteomyelitis.10PubMed. Infected subgaleal hematoma in a 4-month-old girl When an abscess has already formed, antibiotics alone are usually not enough, and surgical drainage becomes necessary.
Calcification of Cephalohematomas
A cephalohematoma that does not reabsorb within the first few weeks of life can undergo a process where the trapped blood clots and gradually hardens. The blood beneath the periosteum stimulates new bone growth, and what was once a soft swelling becomes a rigid, bony lump on the infant’s skull.11PubMed Central. A calcified cephalohematoma in a 1-month-old infant requiring surgery This mineralization typically starts at the edges of the hematoma, forming a hard rim, and can eventually involve the entire collection.12The American Journal of the Medical Sciences. Calcified cephalohematoma following minor trauma in a toddler under surveillance for intracranial hygromas
A calcified cephalohematoma can persist for months to years and, if large enough, may cause a noticeable deformity in the shape of the child’s skull.11PubMed Central. A calcified cephalohematoma in a 1-month-old infant requiring surgery In mild cases, parents are often reassured that the skull will remodel as the child grows. When the deformity is significant or cosmetically concerning, surgical removal of the calcified mass may be recommended. This is elective surgery, not an emergency, and is generally performed once the child is old enough to tolerate the procedure safely.
Scalp Hematomas in Contact Sports
Athletes in contact sports regularly sustain blows to the head that produce scalp hematomas. The scalp hematoma itself is rarely the primary concern in a sports context; what matters is what happened to the brain underneath. Sports-related acute subdural hematoma, a bleed between the brain and its outer covering, is a leading cause of death and severe disability in contact sports like American football and judo.13PubMed Central. Current topics in sports-related head injuries: a review
A visible scalp hematoma after a collision should prompt a thorough concussion evaluation. Current guidelines are clear that an athlete diagnosed with a concussion must not return to play the same day and should not resume contact activity until all symptoms have completely resolved.13PubMed Central. Current topics in sports-related head injuries: a review If imaging reveals any structural brain damage or a subdural hematoma, the athlete should not return to contact sports at all. Treating the goose egg with ice while ignoring the mechanism that created it is the mistake to avoid.
When a Scalp Lump Is Not a Hematoma
Not every lump on the scalp is a blood collection from trauma. The differential for a localized scalp mass includes a wide variety of soft-tissue and bony lesions: epidermoid cysts, lipomas, abscesses, reactive lymph nodes, and vascular tumors, as well as bony growths like osteomas and, rarely, metastatic cancer or meningiomas that erode through the skull.14The American Journal of Emergency Medicine. Point-of-care ultrasound identification of a Calvarial hemangioma in the emergency department: a case report
The clinical distinction is usually straightforward when there is a clear history of head trauma. A lump that appears right after a bump, is tender, discolored, and gradually shrinks over days is almost certainly a hematoma. The picture gets less clear when someone notices a scalp lump without remembering any injury, or when a lump persists or grows weeks after an impact. In those situations, imaging and sometimes biopsy are needed to rule out other causes. A lump that is growing, pulsatile, painless, or has been present for more than a few weeks without changing deserves medical attention.
Scalp Hematomas and Child Abuse Evaluation
In pediatric medicine, scalp hematomas sometimes appear in contexts where the reported mechanism of injury does not match what clinicians see. Subgaleal hematomas caused by shearing forces, such as forceful hair-pulling, can be a sign of non-accidental trauma. Radiological literature refers to this pattern as “scalping,” reflecting the considerable blunt force needed to separate the scalp layers in this way.15PubMed Central. Subgaleal hematoma in child abuse
Clinicians evaluating a child with a scalp hematoma consider the child’s age, the story of how the injury happened, whether the location and severity of the hematoma are consistent with that story, and whether there are other injuries elsewhere on the body. An unexplained or inconsistent scalp hematoma in a young child, especially a subgaleal hematoma without a clear high-force mechanism, can trigger a formal child-protection evaluation. This is one of the reasons that pediatric emergency physicians take scalp hematomas in infants and toddlers seriously even when the swelling itself appears manageable.
People on Blood Thinners Need Extra Caution
If you take warfarin, a direct oral anticoagulant, or even daily aspirin, any head bump deserves more attention than it would for someone not on these medications. Anticoagulation does not just raise the risk of intracranial bleeding; it makes extracranial bleeding more persistent too. A hematoma that would normally be self-limiting can expand slowly over hours or days because the blood is not clotting effectively.
For people on anticoagulants, the general advice after a head injury is to seek medical evaluation even if you feel fine initially. The risk factors that predict the most serious anticoagulant-related hemorrhages, including older age, high blood pressure, and a history of prior stroke, overlap heavily with the population that is most commonly prescribed these drugs.3Stroke. Oral anticoagulants and intracranial hemorrhage. Facts and hypotheses Monitoring in the emergency department, including a CT scan and sometimes a period of observation, is standard practice in many hospitals for anticoagulated patients who have sustained even minor head trauma.