A hematoma is a collection of blood that forms outside of blood vessels, typically resulting from injury or trauma. This pooling occurs when a blood vessel wall is damaged, allowing blood to leak into surrounding tissues or body spaces. While most hematomas are minor and resolve naturally within days to a few weeks, some can persist for months or even years. Understanding the nature of these blood collections is important, as persistent cases may require medical attention.
Understanding Hematomas
A hematoma is a localized pooling of blood within tissues or body spaces, distinct from a simple bruise. Bruises involve leakage from smaller, superficial blood vessels, leading to visible discoloration. In contrast, a hematoma signifies a more significant collection of blood, often from larger blood vessels, which can form a palpable lump or swelling. Hematomas can occur anywhere in the body, including just under the skin (subcutaneous), within muscles (intramuscular), or in critical internal locations like the brain (intracranial).
The body typically initiates a natural healing process for hematomas, where the pooled blood is gradually reabsorbed over time. This process involves the breakdown of blood components, which often causes the characteristic color changes of a resolving bruise, transitioning from dark red to green or yellow before fading completely. Most minor hematomas resolve within one to four weeks as the body reabsorbs the blood and repairs the damaged vessels. However, the time required for complete resolution varies based on the hematoma’s size and location.
Factors Influencing Hematoma Persistence
Several factors influence how long a hematoma takes to disappear, with some circumstances delaying the body’s natural reabsorption process. The size and depth of a hematoma significantly impact its resolution; larger and deeper collections of blood require more time to heal, potentially taking weeks to months. For instance, a small superficial hematoma might resolve quickly, while a substantial intramuscular hematoma could persist for a longer duration.
The location of a hematoma also plays a role in its persistence. Hematomas in areas with less blood flow or in confined spaces, such as joints or within the skull, tend to resolve more slowly or can cause more severe complications due to pressure on surrounding tissues. Internal hematomas in organs like the liver or spleen may also present unique challenges for healing.
Underlying medical conditions can impede a hematoma’s resolution. Individuals with bleeding disorders, liver disease, or those taking anticoagulant medications (blood thinners like warfarin or aspirin) are at an increased risk for larger hematomas and prolonged bleeding, which slows healing. These conditions impair the body’s ability to form stable clots and effectively reabsorb the pooled blood.
Repeated trauma or re-bleeding into an existing hematoma can further delay its resolution. If the injured area experiences new impact or if the damaged blood vessel continues to leak, the hematoma may enlarge or remain present for an extended period. This repeated bleeding can lead to a cycle that prevents complete reabsorption.
Age can also influence the healing process, with older individuals often experiencing slower resolution of hematomas. As people age, their blood vessels can become more fragile, and the skin thinner, making them more prone to bruising and prolonging recovery. Patients over 65, and particularly those over 70, may face a heightened risk of persistent hematomas after injury or surgery.
When Hematomas Persist
When a hematoma does not resolve within the typical timeframe, it can become a “chronic hematoma,” persisting for months or even years. This often occurs because the body, unable to fully reabsorb the blood, may encapsulate or wall off the collection. This encapsulation forms a fibrous membrane around the blood, which can prevent further reabsorption and sometimes even continue to leak fluid or bleed, potentially causing the hematoma to grow.
The symptoms associated with persistent hematomas vary significantly depending on their location and size. Superficial chronic hematomas might present as a firm, discolored lump that causes discomfort or tenderness. Deeper hematomas, especially those pressing on nerves or organs, can lead to more serious issues like pain, swelling, restricted movement, or nerve symptoms such as numbness or weakness.
A notable example of a persistent hematoma is a chronic subdural hematoma (CSDH), which forms between the brain’s surface and its outer protective membrane. CSDHs are more common in older adults, often developing weeks or months after even a minor head injury due to the slow leakage of blood from fragile bridging veins. Symptoms can be subtle and gradually worsen, including headaches, confusion, memory issues, balance problems, or weakness on one side of the body.
Another type is a calcified hematoma, where the body deposits calcium within the blood clot, causing it to harden over time. This calcification can occur when the body fails to fully reabsorb the pooled blood, leading to a firm, sometimes painful, lump that may feel like a bone fragment. While not always dangerous, calcified hematomas can restrict movement or compress surrounding structures, potentially requiring intervention.
Persistent hematomas are not always benign and may signal an ongoing issue or lead to complications. Their continued presence, especially if symptomatic or growing, warrants medical evaluation to determine the underlying cause and appropriate management.
Diagnosis and Management of Persistent Hematomas
When a hematoma persists, medical evaluation is important, especially if it is not resolving, continues to grow, or causes new or worsening symptoms. Seeking prompt medical attention is advised for severe pain, signs of infection like increased warmth or redness, or if the hematoma is associated with a head injury or occurs in individuals taking blood-thinning medications. These situations may indicate a more serious issue requiring intervention.
Diagnosis typically begins with a physical examination, where a healthcare provider assesses the size, location, and characteristics of the swelling. Imaging tests are frequently used to visualize internal hematomas and determine their extent. Computed tomography (CT) scans are often employed for head injuries to check for brain involvement, while ultrasound can be useful for superficial or abdominal hematomas. Magnetic resonance imaging (MRI) provides detailed views of soft tissues, helping to assess the hematoma’s size and if it is pressing on surrounding structures. Blood tests may also be conducted to evaluate clotting function or identify underlying medical conditions.
Management approaches vary depending on the hematoma’s characteristics and symptoms. Small, asymptomatic hematomas may only require observation, with the body eventually reabsorbing the blood. Pain can be managed with appropriate medications, though certain over-the-counter pain relievers like aspirin should be avoided as they can increase bleeding.
For larger or symptomatic hematomas, more direct interventions may be necessary. Aspiration involves using a needle and syringe to drain the accumulated blood, often for superficial collections. Surgical evacuation may be performed for significant hematomas, particularly those causing pressure on organs, nerves, or the brain. This procedure involves an incision to remove the blood clot and relieve pressure. Addressing any underlying medical conditions contributing to the hematoma’s persistence, such as bleeding disorders or uncontrolled hypertension, is also a crucial part of comprehensive management to improve the long-term outlook.