Thrombosis

Thrombosis is when a blood clot forms inside a blood vessel, stopping blood from flowing properly.

When a blood vessel gets hurt, the body makes clots to stop the bleeding. These clots are made from tiny parts in the blood called platelets and a substance called fibrin.

Sometimes, clots can form even when there is no injury. If a clot breaks apart and starts moving, it is called an embolus. This can block blood flow to important parts of the body and cause serious problems like a stroke or a heart attack.

Thrombosis can happen in both veins (venous thrombosis) and arteries (arterial thrombosis). In veins, it often causes a clot in the leg, known as deep vein thrombosis (deep vein thrombosis). In arteries, it can cut off blood to tissues. Pieces of these clots can break off and travel to other parts of the body, which can lead to a pulmonary embolism in the lungs (pulmonary embolism).

Signs and symptoms

Thrombosis is when a blood clot forms inside a blood vessel. It shows different signs depending on where the clot forms.

Arterial thrombosis

Arterial thrombosis happens when a clot forms in an artery. This often occurs after a fatty buildup in the artery wall breaks open. These clots can move and affect other parts of the body. A common cause is irregular heart rhythms.

Stroke

Main article: Stroke

A stroke happens when blood flow to the brain is disturbed, often because of a clot. In thrombotic stroke, a clot usually forms around fatty buildup in the arteries. The symptoms can appear slowly.

Myocardial infarction

Main article: Myocardial infarction

A heart attack occurs when a clot blocks an artery to the heart. This can be very serious and needs quick medical help.

Limb ischemia

A clot can form in the arms or legs, causing problems with blood flow.

Venous thrombosis

Main article: Venous thrombosis

Deep vein thrombosis

Main article: Deep vein thrombosis

Deep vein thrombosis (DVT) is when a clot forms in a deep vein, usually in the legs. Signs include swelling, pain, and redness.

Paget-Schroetter disease

Main article: Paget-Schroetter disease

Paget-Schroetter disease is a type of clot in an arm vein. It is often noticed after heavy exercise. It usually affects young, healthy people.

Budd-Chiari syndrome

Main article: Budd-Chiari syndrome

Budd-Chiari syndrome happens when a vein in the liver gets blocked. This can cause swelling in the abdomen and an enlarged liver.

Portal vein thrombosis

Main article: Portal vein thrombosis

Portal vein thrombosis affects the vein that carries blood to the liver. It can reduce blood flow to the liver.

Renal vein thrombosis

Main article: Renal vein thrombosis

Renal vein thrombosis blocks the vein that drains blood from the kidney. This can reduce drainage from the kidney.

Cerebral venous sinus thrombosis

Main article: Cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis is a rare type of stroke caused by a clot in the brain’s venous sinuses. Symptoms can include headaches, vision problems, and weakness.

Jugular vein thrombosis

Jugular vein thrombosis can happen due to infection or other causes. It may lead to serious complications.

Cavernous sinus thrombosis

Main article: Cavernous sinus thrombosis

Cavernous sinus thrombosis is a specialized type of brain vein clot. It can cause symptoms like double vision.

Causes

Thrombosis happens when a blood clot forms inside a blood vessel, stopping blood from flowing properly. Some people have a higher chance of getting this because of things like inflammation.

There's something called Virchow's triad that talks about three main things that can lead to thrombosis: changes in blood flow, problems with the blood vessel walls, and the blood being more likely to clot. Some risk factors make it more likely for clots to form in veins, while others make it more likely in arteries. Even newborn babies can sometimes get these clots.

Mechanism

Main article: Virchow's triad

Thrombosis is when a blood clot forms inside a blood vessel and blocks blood flow. This can happen for a few main reasons, which are part of Virchow's triad. These reasons include certain body conditions that make clotting easier, injury to the blood vessel lining, and changes in blood flow.

As people get older, their risk for thrombosis can go up. This can be because of things like smoking, diet, not exercising, and other health problems.

If the lining of a blood vessel gets damaged, for example from an injury, surgery, or infection, it can cause the body to make clots. When blood flow changes, like when blood slows down or pools, it can also make clots more likely. This can happen after sitting for a long time, such as during a long airplane flight, or in some heart problems. Certain diseases, like cancer, can also increase the risk of blood clots.

Prevention

After surgery, doctors may give a medicine called heparin to help stop blood clots from forming. They are careful with this medicine because it can sometimes cause bleeding.

Blood clots can be dangerous and may cause serious problems. To help prevent this, doctors use special methods, like stockings, to keep blood moving. In some cases, they might use other medicines or place a filter to protect the blood flow. These steps help keep people safe when they are in the hospital.

Treatment

The way to treat thrombosis depends on where it is in the body, how it affects the person, and the chance of problems from treatment.

Anticoagulation

The main article is: Anticoagulant

Medicines like Warfarin and vitamin K antagonists can be taken by mouth to help stop blood clots from forming. In some cases, a medicine called heparin may be given by injection. These medicines can sometimes cause bleeding, so doctors watch the blood closely. Some people can manage their treatment at home. Other medicines like direct thrombin inhibitors and direct Xa inhibitors are also used now instead of Warfarin.

Thrombolysis

Thrombolysis uses special medicines to break down blood clots. This can be risky because it may cause bleeding, so it is usually only used in serious cases like severe stroke or a big blockage in the lungs.

Surgery

If a blood clot in an artery causes serious problems in a limb, surgery might be needed.

Endovascular treatment

In some cases, doctors can remove the clot using special tools through a tube.

Antiplatelet agents

For blood clots in arteries, medicines like aspirin can help stop more clots from forming.

Targeting ischemia/reperfusion injury

The main article is: Reperfusion injury

When blood flow returns to an area that didn’t have blood for a while, it can sometimes harm the tissues. This happens in certain heart conditions. Doctors are studying ways to protect the tissues during these treatments.

Neonatal thrombosis

For babies who develop blood clots, treatments can include watching closely, using special ointments, medicines, or surgery. However, there isn’t strong evidence to show which treatments work best for babies, and more research is needed.