Hematoma is a medical term that refers to a collection of blood outside of a blood vessel. The word hematoma comes from the Greek word “haima” meaning blood. So literally, hematoma means a swelling or mass of blood. Hematomas most commonly occur when a blood vessel is damaged and leaks blood into surrounding tissues where it does not belong. This causes the blood to pool and form a swelling or lump. So in short, yes hematoma does mean bleeding.
What is a hematoma?
As mentioned, a hematoma is a collection of blood that has leaked out of a damaged blood vessel into surrounding tissues. This pooling of blood forms a swelling or lump under the skin. Hematomas can occur anywhere in the body but are most common in skin, muscles, and internal organs.
There are several types of hematomas depending on where they form:
- Scalp hematoma – collects between the skull and the scalp, usually due to head injury
- Ear hematoma – forms on the ear, often in dogs and cats
- Subungual hematoma – under a fingernail or toenail
- Intramuscular hematoma – within a muscle, often caused by trauma
- Retroperitoneal hematoma – behind the abdominal lining, usually after surgery
- Subdural hematoma – between the brain and its outermost covering, due to head injury
- Hematoma of the ear – caused by trauma or blood thinners
Hematomas can range in size from a tiny dot to a large mass many centimeters across. They may be superficial and visible just under the skin, or located deep inside the body cavities and organs.
What causes a hematoma?
Hematomas are caused by damage to a blood vessel that causes bleeding. There are several ways this can happen:
- Trauma – Any significant impact to the body that crushes blood vessels can lead to bleeding and hematoma formation. Common causes are falls, vehicle accidents, sports injuries, and head trauma.
- Surgery – Surgical procedures that involve cutting and manipulating tissues can damage blood vessels and cause postoperative hematomas.
- Medical procedures – Needle biopsies, epidural injections, venipuncture, and other invasive tests can damage blood vessels enough to cause localized hematomas.
- Medications – Blood thinners or anticoagulants reduce blood clotting which allows even minor trauma to result in prolonged bleeding under the skin.
- Bleeding disorders – Conditions like hemophilia prevent blood from clotting normally, increasing risk of hematoma formation.
- Infection – Infections can cause inflammation and damage to blood vessels.
- Cancer – Tumors can erode blood vessels causing leakage.
In most cases, a specific incident of trauma or vascular damage can be identified as the cause of a hematoma. However, sometimes no cause can be found.
Signs and symptoms
The most common sign of a hematoma is a visible, swollen lump under the skin that is tender and sometimes firm to the touch. The lump is caused by the pooled blood.
Other symptoms can include:
- Bruising or discoloration as blood leaks into tissues
- Pain or tenderness when pressure is applied
- Difficulty moving the affected body part
- Numbness or tingling if nerves are compressed
The size and location of the hematoma will determine the symptoms. A large hematoma in the retroperitoneal space behind the abdomial lining can go unnoticed, while a tiny hematoma on the forehead may be very obvious.
Symptoms of internal bleeding in the skull or abdomen may include:
- Sudden, severe headache
- Dizziness
- Vision changes
- Confusion
- Nausea and vomiting
- Abdominal pain
- Fainting
These are signs of serious, potentially life-threatening internal bleeding and require emergency medical care.
Are bruises and hematomas the same thing?
Bruises and hematomas are sometimes used interchangeably, but there are subtle differences:
- A bruise (contusion) refers to bleeding under the skin, while a hematoma is a distinct pool of blood.
- Bruises tend to be diffuse, with blood spreading in tissues. Hematomas are circumscribed lesions.
- Minor leaks from tiny capillaries cause bruises. Larger vessels damaged causes hematomas.
- Bruises are not usually palpable lumps. Hematomas usually form a noticeable lump.
However, bruises and hematomas both indicate bleeding under the skin. They exist on a spectrum, with bruises being a minor subdermal bleed and hematomas being a more extensive, localized collection of blood.
Table comparing bruises and hematomas
| Feature | Bruise | Hematoma |
|---|---|---|
| Cause | Leakage from tiny capillaries | Damage to larger blood vessels |
| Appearance | Diffuse, spreading | Circumscribed, localized |
| Palpable lump? | Usually no | Usually yes |
Are hematomas serious?
Most hematomas, like those under fingernails or superficial ones on the arms and legs, are minor and not serious. However, hematomas in certain locations or situations can be very serious and require prompt medical care:
- Subdural hematomas – Bleeding between the brain and its outer covering puts extreme pressure on the brain and can be fatal if not drained.
- Retroperitoneal hematomas – Bleeding into the abdominal cavity behind organs can cause blood loss shock.
- Ocular hematoma – Bleeding inside or behind the eyeball damages delicate eye tissues.
- Spinal epidural hematoma – Bleeding inside the spinal canal compresses the spinal cord and nerves.
In addition, patients taking blood thinners or who have bleeding disorders are at higher risk of excessive blood loss and shock from any hematoma, no matter how minor it seems.
Whenever a hematoma causes significant pain, swelling, numbness, or neurological symptoms, it should be evaluated by a doctor. Surgery may be required to drain or decompress large hematomas.
Treatment for hematomas
Treatment for a hematoma depends on its location and size, but may include:
- Rest – Avoid using or putting pressure on the affected area to allow healing.
- Ice – Applying ice can help reduce swelling and pain.
- Compression – Pressure, bandages, or casts provide support and limit swelling.
- Elevation – Keeping the area raised above heart level aids drainage.
- Medications – Over-the-counter pain relievers or prescription steroids may be given.
- Procedures – Drainage, aspiration, or surgery may be needed to remove large hematomas.
Most small hematomas heal completely as the blood is slowly reabsorbed. Larger ones may leave some residual bruising or discoloration under the skin after healing. Physical therapy is sometimes needed to regain strength and mobility after the acute injury heals.
Are there any complications from hematomas?
Potential complications of untreated or severe hematomas include:
- Hypovolemic shock – Significant blood loss into tissues can lead to dangerously low blood pressure.
- Compartment syndrome – Pressure buildup inside a muscle compartment can damage tissues.
- Infection – Hematomas can become infected if bacteria enter the site.
- Skin necrosis – Extensive bleeding under the skin can cut off blood supply and cause tissue death.
- Contracture – Muscles and other structures may scar down and cause permanent shortening or dysfunction.
Patients at highest risk include those taking anticoagulants or blood thinners, as even minor bleeding episodes can progress unchecked. Seeking prompt medical treatment is important, especially with large or expanding hematomas.
Table of potential hematoma complications
| Complication | Description |
|---|---|
| Hypovolemic shock | Dangerously low blood pressure due to blood loss |
| Compartment syndrome | Raised pressure inside a muscle compartment damages tissues |
| Infection | Hematoma site can become infected if exposed to bacteria |
| Skin necrosis | Loss of skin blood supply leads to tissue death |
| Contracture | Permanent shortening or dysfunction due to scarring |
When to see a doctor
Seek prompt medical attention for:
- Very large hematomas
- Quickly expanding hematomas
- Hematomas associated with pain, numbness or loss of function
- Hematomas on the face, spine, abdomen, or skull
- Suspected internal bleeding
- Patients on blood thinners with any abnormal bleeding
- Signs of shock such as low blood pressure, rapid heart rate, dizziness or fainting
Small, superficial hematomas that do not cause other symptoms can often be managed at home. But extensive bleeding, hematomas in delicate areas, and signs of internal bleeding are medical emergencies requiring hospital treatment.
Can hematomas be prevented?
It is not always possible to prevent a hematoma, particularly if it is caused by trauma or surgery. But the following precautions may help reduce the chances of developing a hematoma:
- Use protective gear for sports and dangerous work
- Address any bleeding disorders or vitamin deficiencies
- Be very cautious taking blood thinners or antiplatelet medications
- Follow all post-surgical instructions carefully
- Promptly treat any infections that could erode blood vessels
- Use compression garments to stabilize vulnerable tissues
While some risk factors cannot be avoided, taking appropriate precautions during high-risk activities, managing health conditions properly, and promptly treating any emerging hematomas can help prevent severe outcomes.
Conclusion
In summary, hematoma refers to a collection of blood outside of a blood vessel, usually caused by trauma damaging a blood vessel wall. The pooled blood forms a visible swelling or lump under the skin. Hematomas in the skin, muscle, or body cavities are common. Most are minor, but they can potentially be serious depending on their location and size.
Hematomas differ from bruises in being more localized masses rather than diffuse areas of bleeding. However, both indicate bleeding underneath the skin due to damaged blood vessels.
Treatment depends on the hematoma but may involve rest, ice, compression, elevation, medications, draining procedures, or surgery. Prompt medical care is needed for large, expanding, or potentially dangerous hematomas. Small hematomas often heal on their own over weeks as the blood is reabsorbed.
While some hematomas are unavoidable, taking precautions to prevent trauma and managing health conditions can help reduce risk. But any significant, abnormal bleeding or unexplained hematomas warrant medical evaluation to prevent potentially serious outcomes.