A hematoma is a collection of blood outside of a blood vessel. It occurs because of an injury to the wall of a blood vessel, allowing blood to seep out into the surrounding tissues. Hematomas can occur anywhere in the body, but are most commonly seen under the skin. This results in a visible lump or bump under the skin, which is often blue/purple in color. A hematoma lump may be alarming to notice, but it is generally not a serious condition. In most cases, the body reabsorbs the collected blood within a few weeks and the hematoma resolves on its own without treatment. However, sometimes a hematoma lump can persist longer than expected. This article will provide an overview of hematomas and discuss whether it is possible for a hematoma lump to become permanent.
What Causes a Hematoma?
A hematoma starts when a blood vessel wall is damaged. This damage allows blood to leak out of the blood vessel into the surrounding tissues. There are several potential causes of blood vessel injury that can lead to a hematoma, including:
- Trauma – Direct blows, damage from penetrating objects, or crush injuries can rupture blood vessels and cause localized bleeding.
- Surgery – Surgical procedures that involve cutting through tissue can damage blood vessels.
- Medications – Blood thinners or anticoagulants prevent blood clotting, which makes it easier for bleeding to occur if a blood vessel is damaged.
- Medical conditions – Certain health problems like blood clotting disorders or connective tissue diseases increase susceptibility to hematomas.
- Spontaneous – Sometimes the walls of blood vessels can spontaneously weaken and burst, resulting in unprovoked bleeding.
Once bleeding starts, blood accumulates and pools within the surrounding tissues, creating the visible hematoma lump. The size of the hematoma depends on the degree of bleeding and location. Small capillaries may leak small amounts, while larger veins or arteries can produce massive hematomas.
Body’s Response to Hematoma
When a hematoma first forms, the body triggers the coagulation cascade and fibrinolysis in an attempt to stop the bleeding. The coagulation cascade activates platelets and plasma proteins to form a fibrin clot at the site of blood vessel injury. Fibrinolysis breaks down the clot once healing begins. As the body works to halt further bleeding, the pooled blood solidifies into a rubbery lump within the tissues.
Over time, the hematoma lump will start to shrink and be reabsorbed. White blood cells called macrophages migrate into the area and break down the solidified blood through a process called phagocytosis. The iron released from broken down red blood cells gets recycled or stored, while the remaining hematoma fluid drains away. This entire process is called hematoma resolution.
In most straightforward cases, a minor hematoma lump resolves within 1-2 weeks. Larger hematomas or ones in areas with poor circulation may take 4-6 weeks to fully reabsorb. As the hematoma breaks down, the skin overtop will change color as hemoglobin degrades – often turning green, yellow, or brown. The size, location, and amount of damage affects the timeline of resolution.
Can a Hematoma Lump Become Permanent?
In the majority of cases, hematoma lumps are temporary and will disappear as the body heals itself. However, there are some situations in which it is possible for a hematoma to become a permanent lump or mass:
- Recurrent bleeding – If the damaged blood vessel does not heal properly and bleeding occurs again, it can lead to a chronic hematoma.
- Calcification – Sometimes calcium deposits form within the solidified blood, creating an area of hard calcification that remains as a lump.
- Fibrosis – The body may heal the area with fibrous scar tissue rather than reabsorbing the hematoma, leaving a fibrous lump.
- Compartment syndrome – Pressure buildup in an enclosed space can impair hematoma resolution.
- Infection – Contamination and infection can cause a hematoma to turn into an abscess.
- Location – Hematomas in confined spaces, like the ear, are less likely to resolve.
- Medical conditions – Diseases that affect wound healing make it harder for hematomas to resolve.
These situations disrupt the natural hematoma healing process and cause the lump to persist. Let’s take a closer look at some specifics:
Recurrent Bleeding
If the injured blood vessel does not fully heal, it is possible for repeated bleeding episodes to occur. More blood leaks out with each recurrence, accumulating into a chronic or growing hematoma. This often happens if anticoagulant medications are being used. Preventing re-injury to the area helps minimize the risk of this occurring. Using compression, activity modification, and monitoring for medication interactions can help.
Calcification
The body sometimes deposits calcium into the area of injury as part of the healing response. This calcium can build up within the solidified blood of a hematoma. Over time, this creates a firm, calcified mass – essentially turning the hematoma into a stone-like lump. These calcium deposits remain permanent unless surgically removed.
Fibrosis
Fibrosis refers to the formation of fibrous scar tissue at the site of injury. Instead of macrophages breaking down and reabsorbing the hematoma, fibroblasts may lay down collagen fibers and create a fibrous mass. The fibers encapsulate and wall off the hematoma, preventing its resolution. These firm, fibrous lumps remain unless the scar tissue is surgically released.
Compartment Syndrome
Compartment syndrome occurs when pressure builds up within an enclosed anatomical space filled with muscle and tissue. This pressure buildup compromises circulation and prevents normal hematoma reabsorption. Compartment syndrome often affects the lower leg, forearm, hand, foot, and thigh – areas enclosed by fascial compartments. Emergency surgery is required to relieve the pressure and restore blood flow.
Infection
If bacteria contaminate the area of bleeding, the hematoma can become infected. This turns it into an abscess filled with pus and irritated tissue. Abscesses do not resolve naturally and require draining by a doctor. Contamination is a particular risk with traumatic penetrating injuries. Signs of infection include redness, swelling, warmth, pus drainage, fever, and red streaking.
Location
Due to structural restraints, hematomas located in certain areas struggle to resolve. These include the ear canal, nasal passages, throat, within the skull, and in confined joint spaces. The drainage pathways are restricted, preventing the body from effectively breaking down and reabsorbing the blood. Surgical procedures are often necessary to treat hematomas in these locations.
Medical Conditions
Certain conditions and diseases can impair the body’s natural ability to heal and resolve hematomas. These include blood clotting disorders, autoimmune diseases, diabetes, atherosclerosis, and renal disease. Medications like corticosteroids and chemotherapy also slow healing. Treating the underlying condition can improve hematoma resolution.
When to Seek Medical Care
Many minor hematomas resolve without intervention. However, it is important to seek prompt medical care if:
- The hematoma develops rapidly or seems to be expanding in size
- Signs of infection are present
- Numbness, tingling, coolness, or change in skin color distal to the lump develops (signs of compromised circulation)
- The lump persists longer than 1 month without improvement
- The hematoma is extremely large or located over delicate structures like the eye
- You are taking anticoagulant medications like warfarin (increased bleeding risk)
Providing a doctor with details about the injury mechanism, timing, and lump progression is helpful. Based on the assessment, the doctor may order imaging tests like CT, MRI, or ultrasound to evaluate the hematoma. Treatment depends on the location, size, and suspected cause. Options range from careful monitoring to medications, drainage procedures, surgery, or other interventions aimed at preventing recurrence and supporting resolution.
Table Summarizing Key Hematoma Characteristics
| Type | Location | Cause | Appearance | Resolution Time |
|---|---|---|---|---|
| Minor bruising | Skin/subcutaneous | Light trauma | Blue/purple, small | 1-2 weeks |
| Traumatic | Muscle/joints | Injury, fall, blow | Tender swelling, bruising | 2-6 weeks |
| Post-op | Incision site | Surgical bleeding | Fluid-filled mass | 2-8 weeks |
| Anticoagulant | Variable | Medication effects | Large, spontaneous | Prolonged, recurrent |
| Calcified | Variable | Calcium deposits | Firm, hardened | Permanent |
Conclusion
In summary, most hematoma lumps are not permanent and will gradually resolve as the body reabsorbs the blood. However, there are situations in which it is possible for a hematoma to persist as a long-term lump or mass. Recurrent bleeding, calcification, fibrosis, infection, and challenging locations can all impair natural resolution. Certain medical conditions also make it harder for hematomas to heal. Persistent or worsening hematomas should be evaluated by a doctor to identify any underlying issues that require treatment. With proper care, even complicated hematomas can often be resolved or managed to prevent permanence.
