What is a Blood Clot, Thrombus or Embolus in Vein or Artery?

The blood is a liquid medium containing many chemicals, small particles, blood cells and proteins. When needed, these components of the blood can act together to form a gelatinous plug to stop blood loss. A blood clot is normally formed by the body in its attempt to repair an injured blood vessel. The injury may be obvious with signs of bleeding or it may be too minute to be visible. A blood clot that forms in normal circumstances is beneficial and life-saving, but if it occurs without just cause it may lead to problems.

What is a Blood Clot?

Explanation of blood clots

A blood clot is essentially a plug of blood proteins and cells that seals a break in a blood vessel to stop bleeding. When a blood clot forms within a blood vessel (artery or vein) or within a chamber of the heart (atrium or ventricle) and remains there it is called a thrombus. A thrombus may be large enough to block the blood vessel and prevent blood flow, when the condition is known as thrombosis, such as deep venous thrombosis (DVT).

If the blood clot gets dislodged and travels along the blood vessel to some other part of the body, it is known as an embolus. When an embolus gets lodged within a narrow vessel, it blocks the circulation there and causes a condition known as embolism, such as pulmonary embolism if a clot lodges into a blood vessel in the lung.

How is a Blood Clot Formed?

Formation of a blood clot

Blood flows in the liquid form in blood vessels. It consists of the fluid plasma along with red blood cells, white blood cells, and platelets. The platelets are actively involved in the blood clotting process. Any damage to the lining of the blood vessels results in platelet aggregation at that point, with the formation of a platelet plug at the injury site.

A platelet plug is not a blood clot but forms rapidly to minimize blood loss until the clot can develop over it. Other clotting factors are released which ultimately results in fibrin formation – a protein mesh that traps other blood components to form the blood clot. One of the causes is due to thick consistency of blood because of high sugar intake.

Where can a Blood Clot Form?

Sites of Blood Clots

Clots can occur in veins, arteries or chambers of the heart.

• Vein – clots in the vein or venous thrombosis usually occurs due to prolonged immobilization. DVT (deep vein thrombosis) occurs most commonly in a major vein in the leg and its most fearsome complication is pulmonary embolism.
• Artery – clots in arteries are usually associated with atherosclerosis which is the hardening and narrowing of arteries due to deposition of plaque. When blood supply to the heart or brain is compromised due to partial or complete blockage of the artery, it can lead to a heart attack, stroke, or even death.
• Heart – clots may form in the heart due to stagnation of blood in the atrium (in atrial fibrillation) or ventricle (after a heart attack). Pulmonary embolism may be a complication.

Clots can also form in other situations, such as is the case of :

• Vaginal bleeding
• Bleeding peptic ulcer
• Rectal bleeding
• Urinary tract infection
• Bladder infection

Who is at risk of a blood clot?

Risk Factors for Blood Clots

Patients with one or more of these risk factors have a greater chance of developing a blood clot in a vein or artery.

Venous (Vein) Blood Clots

• Obesity
• Prolonged immobilization, such as after major surgery or long hours of travel like international flights.
• Pregnancy
• Cigarette smoking
• Oral contraceptives
• Family history
• Age over 60

Arterial (Artery) Blood Clots

• Obesity
• Lack of exercise (sedentary lifestyle)
• Cigarette smoking
• Diabetes mellitus (sugar diabetes)
• High blood pressure
• High cholesterol
• Family history

How is a blood clot treated?

Treatment of a blood clot

Treatment will depend upon the site of the clot and the symptoms present, amongst other considerations. The treatment may involve breaking down the clot, preventing further clot formation, opening and widening the affected blood vessel or even surgical removal of the clot. The following terms explains the medication and procedures that may be used in this regard :

• Anticoagulants – to prevent clotting
• Fibrinolysis (clot busters) – to dissolve clots
• Catheterization of the vessel and stenting
• Thrombectomy – surgical removal of clot

Dr. Maya Patel

She is a renowned neurologist, illuminates the path to optimal brain health. Her expert insights guide individuals to understand and nurture their brain, ensuring mental clarity, resilience, and well-being.