The formation or presence of a blood clot in a blood vessel. The vessel may be any vein or artery as, for example, in a deep vein thrombosis or a coronary (artery) thrombosis. The clot itself is termed a thrombus. If the clot breaks loose and travels through the bloodstream, it is a thromboembolism.

Alternative Names of Thrombosis are: Deep Venous Thrombosis.

Complications of Thrombosis

Complications of Thrombosis are secondary conditions, symptoms, or other disorders that are caused by Thrombosis. In many cases the distinction between symptoms of Thrombosis and complications of Thrombosis is unclear or arbitrary. The list of complications that have been mentioned in various sources for Thrombosis includes:

• Thromboembolism
• Embolism
• Pulmonary embolism
• Pulmonary thromboembolism
• Heart attack - from arterial thrombosis
• Stroke - from arterial thrombosis

Causes of Thrombosis

Thrombosis occurs when a blood clot forms within a vein or an artery, slowing or stopping the flow of blood.

How the blood clots
Your blood contains cells called platelets and proteins, known as clotting factors, which together make up the blood-clotting mechanism. When a blood vessel is cut, the platelets and clotting factors in your blood mesh together to form a solid clot at the site of the wound. This clot acts as a plug to stop the wound bleeding. Normally, the blood-clotting mechanism is only triggered when a blood vessel is damaged and bleeds, such as when you cut yourself. Sometimes the blood may start to clot even when a blood vessel has not been damaged. If this happens, a blood clot can form within a vein or artery (thrombosis).

Thrombosis can occur for many different reasons. The main risk factors are:

• getting older,
• being inactive or immobile for long periods of time,
• having a previous blood clot,
• having a previous heart attack or stroke,
• having a member of your family with a blood clot,
• cancer,
• taking the combined contraceptive pill or hormone replacement therapy (HRT),
• a condition such as thrombophilia that makes your blood more likely to clot,
• high blood pressure (hypertension),
• high cholesterol levels,
• pregnancy,
• smoking,
• a poor diet,
• being obese, and
• Having an operation on the lower half of your body.

However, the three main causes of thrombosis are:

• slow blood flow,
• blood clotting too easily, and
• Blood vessel damage.

In some cases, thrombosis may occur due to a combination of these factors.

Signs & Symptoms of Thrombosis

In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms.

When signs and symptoms of deep vein thrombosis occur, they can include:

• Swelling in the affected leg, including swelling in your ankle and foot.
• Pain in your leg; this can include pain in your ankle and foot. This pain often starts in your calf and can feel like cramping or a "charley horse."
• Redness and warmth over the affected area.
• Pain or swelling in your arms or neck. This can occur if a blood clot forms in your arms or neck.

Diagnosis of Thrombosis

• Three tests have good accuracy for diagnosing Deep Vein Thrombosis (DVT) in symptomatic patients: venography, impedance plethismography (IPG) and duplex venous ultrasound (B - mode imaging). In most patients with clinically suspected venous thrombosis, venous ultrasound is the diagnostic method of choice.
• In addition, the simpli -red -D-dimer test, which is performed on blood obtained by finger prick at the patient’s side and which has high sensitivity and moderate specificity, shows considerable promise as a test to rule out venous thrombosis. The D-dimer test is often false-positive after surgery or trauma, thereby limiting its value in these clinical situations
• Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are also useful in some circumstances. Venography, although invasive, is the “gold standard” diagnostic procedure, and the best noninvasive substitute for venography is duplex ultrasound.

Treatments of Thrombosis

• Patients often require long-term anticoagulant treatment, and subsequently its efficacy, safety and impact on quality of life are of great importance. Currently available treatments for the management of thrombosis, although effective, are associated with a number of drawbacks.
• Vitamin K antagonists (VKAs) - for example, warfarin - have been the standard long-term anticoagulant therapy for almost 60 years. However, drawbacks associated with warfarin include drug and food interactions and the need for routine coagulation monitoring. People receiving VKAs therefore have to go to their doctor or to the lab at least once a month, and sometimes even more frequently, to have their blood tested and dose adjusted. Taking the wrong dose will lead to an increased risk of bleeding or stroke.
• Low molecular weight heparins (LMWHs) require subcutaneous or intravenous administration, and so are inconvenient to use outside the hospital environment and are unsuitable for long-term treatment.
• Subsequently, many patients at risk of thrombosis do not receive the anticoagulant therapy they need because of the complications associated with these treatments.

Prevention of Thrombosis

• Preventing thrombosis is essential. Inside a healthy circulatory system, the body constantly prevents clotting. Coagulation/anticoagulation is a "mechanism" that the body must maintain in perfect balance. If this process fails, our lives can be in danger in a matter of minutes.
• To function optimally, the body must keep blood flowing well in all vessels, regardless of size. When a leak (or damage) occurs in an artery or vein, the body must encourage the coagulation aspect of this balance to seal the leak. However, when there is a significant disturbance or a clot in the blood flow, the consequences are often lethal.
• Because so many factors can contribute to coagulation and therefore should be considered for prevention, it is difficult for conventional medicine to control them all. Mainstream medicine can exert control on some crucial steps in the coagulation cascade, but it may often fail to influence them all.

When to seek Medical Advice

Call the healthcare provider immediately if a clot is suspected.

• Although a deep vein thrombosis may resolve on its own, the life-threatening consequences of a clot reaching the lung, called pulmonary embolism, are severe enough to warrant seeking medical attention immediately.
• The healthcare provider may tell the patient to go immediately to a hospital emergency department.
• If the patient has leg pain or swelling with any risk factors, go to a hospital emergency department immediately.