Blood clots are solid masses formed by blood cells clumping together. While this is a normal process for stopping bleeding, a clot forming inappropriately inside a blood vessel can obstruct blood flow. Although the public often associates this condition with the legs (Deep Vein Thrombosis or DVT), a clot can develop in the upper body, including the veins of the hand and arm. This condition is broadly known as Upper Extremity Venous Thrombosis (UEVT).
The Possibility of Upper Extremity Clots
Clots in the veins of the hand and arm are less frequent than those in the legs, accounting for about 5% to 10% of all deep vein thromboses. These clots can occur in the small veins of the hand or in the larger, deeper veins of the arm, shoulder, and neck. The location of the clot helps determine the risk level and required treatment.
The two main types of upper extremity clots are Superficial Venous Thrombosis (SVT) and Deep Vein Thrombosis (DVT). SVT involves the veins just beneath the skin’s surface. DVT of the arm involves larger, deeper veins, such as the axillary or subclavian veins near the shoulder and collarbone. DVT is generally considered more serious due to the potential for complications and is being diagnosed more frequently with the increased use of medical interventions in the upper body.
Recognizing the Warning Signs
Symptoms of a blood clot in the hand or arm often manifest suddenly and progress quickly. The most noticeable sign is usually swelling, which may affect the hand, wrist, or the entire arm. This swelling can be rapid and may not improve with rest or elevation.
Pain is also common, ranging from a dull ache to a sharp, throbbing discomfort that worsens with movement. The affected area may exhibit changes in skin appearance, such as reddish or bluish discoloration, and may feel warm to the touch. A vein affected by a superficial clot may feel firm, tender, and cord-like beneath the skin.
Specific Causes and Risk Factors
The causes of upper extremity blood clots are often distinct from those that occur in the legs. A common factor is the presence of an indwelling medical device, such as a central venous catheter (CVC) or a peripherally inserted central catheter (PICC) line. These lines can irritate the vein wall, creating a site for a clot to form.
Physical damage to the vein, including local trauma, a fracture, or a significant muscle injury, can also trigger clot formation. Repetitive or strenuous activity of the arm, sometimes called “effort thrombosis” or Paget-Schroetter syndrome, is another specific cause. This is often seen in athletes who engage in sports like baseball or swimming.
This effort-related clotting may be linked to Thoracic Outlet Syndrome (TOS), where blood vessels are compressed near the collarbone and first rib. Additionally, underlying health conditions, such as cancer or a pre-existing hypercoagulable state (a genetic tendency for blood to clot easily), increase the risk.
Seeking Prompt Medical Evaluation
A suspected blood clot in the hand or arm requires immediate professional evaluation. Delaying diagnosis and treatment increases the risk of serious complications, including the clot breaking off and traveling to the lungs, resulting in a pulmonary embolism.
A healthcare provider typically uses a non-invasive imaging test, such as an ultrasound with Doppler technology, to visualize blood flow and confirm the clot’s presence and location. The goals of treatment are to prevent the clot from growing, stop it from traveling to the lungs, and minimize long-term vein damage.
Treatment usually involves blood-thinning medications, known as anticoagulants, for several months. If the clot is extensive, additional procedures like catheter-directed thrombolysis, which delivers clot-dissolving medication directly to the site, may be considered. The management plan is tailored to the clot’s cause, location, and the patient’s overall health profile.