What is coagulation?

The circulation of blood is important to make sure the body is working properly. Coagulation (or clotting) is the process through which blood changes from a liquid and becomes thicker, like a gel. Coagulation is part of a larger process called hemostasis, which is the way that the body makes bleeding stop when it needs to.

When coagulation works the way it is supposed to, it is an important step on the way to healing a wound. When a blood vessel breaks, as with a cut or other injury, coagulation helps form a clot, made from a substance called fibrin. The clot seals the hole until the tissues can repair themselves.

When something happens that keeps coagulation from happening, it can lead to bruising, which happens when bleeding happens from small blood vessels under the skin, or to a hemorrhage, which is uncontrolled bleeding. (The word “hemorrhage” is the opposite of hemostasis.)

When coagulation happens where it is not supposed to, it can form a clot that blocks a blood vessel instead of fixing it. Thrombosis is the formation of a blood clot, called a thrombus, inside a blood vessel, that blocks the flow of blood through the circulatory system.

The main causes of thrombosis include conditions that make the blood coagulate more easily, injury to nearby tissues, and conditions that prevent blood from flowing normally. If a thrombus is large enough to reduce the blood flow, it can keep some tissues from getting the oxygen they need. A larger thrombus causing a much greater obstruction to the blood flow may result in tissue death, also called infarction. A blood clot that travels from one place to another in the body is called an embolus.

Disorders of coagulation and hemostasis may be passed along at birth or may develop later. Hemophilia, the most common condition leading to bleeding is an example of a condition that is congenital, or present from birth.


Our approach to coagulation and hemostasis disorders

Our approach to treatment of thrombosis begins with finding out why the blood clot occurred, removing any identifiable risk factors, and sometimes using blood thinners called anti-coagulants to prevent further unwanted clotting. In general, our approach to thrombosis follows the published guidelines of the American College of Chest Physicians. We try to minimize the time a child is on anticoagulation medication while at the time making sure we reduce the risk of the clot getting bigger or coming back.

In some cases, the body does not have enough of the substances it needs to form a blood clot. This can happen because either the individual was not born with enough of these substances (hereditary) or they have a condition that keeps clotting from happening (acquired). Often, patients who have problems forming a clot are referred to us because of unusual bleeding.

During the initial visit we try to understand as quickly as possible the patient’s pattern of bleeding, including asking about any family history of bleeding, and any possible causes for an acquired bleeding condition. This helps us to obtain the best tests and discover the cause of the bleeding.

Hemophilia, the most common coagulation condition that may cause unusual bleeding, is an example of a congenital condition where an important factor needed to make a blood clot is reduced or missing.

Individuals with these conditions, either hereditary or acquired, have a tendency to bleed even without injury. In many cases, we are able to treat these patients by giving back what is missing through infusions. We provide infusions to help children live a life that results in less bleeding episodes, safe involvement in activities, and overall improved quality of life.