Coagulation Tests

Lady performing coagulation profile test

Last Updated December 20th, 2021

What are coagulation tests?

Coagulation tests are investigative blood tests to measure the ability and function of coagulation factors in the blood. The blood examinations measure the capacity and time taken for your blood to clot in the event of an injury. Testing can help your doctor evaluate the threat of uncontrolled bleeding as well as assess the risk of developing clots (thrombosis) in the blood vessels.

Coagulation tests are on the lines of normal blood tests with minimal risks and side effects. 

What are the alternative names for coagulation tests?

Coagulation tests are known by other titles such as factor assays. Factor assays are denoted using numbers or names.  Factor assays with numbers are

Factor 1, Factor II and names are fibrinogen, prothrombin, hemophilia A, and hemophilia B, etc.

What are coagulation factors?

Blood has proteins called coagulation factors that help control bleeding. Coagulation factors are nothing but proteins, mainly calcium and phospholipids which are produced by the liver.

There are many different coagulation factors about 12 in number. Coagulation factors are known with Roman numerals (I, II VIII, etc.) or by names (fibrinogen, prothrombin, hemophilia A, etc.). There is a risk of uncontrolled bleeding after an injury incase any of the factors are absent or  are defective.

During an injury, the coagulation factors come together to help the blood to clot. This protects the body against excessive loss of blood. The coagulation pathway is said to be a cascade of events, which leads to hemostasis.

Blood coagulation process

This process of blood coagulation involves altering the circulating substances in the blood to an insoluble gel. This gel closes the leak in the blood vessels and controls blood loss. This process of coagulation is executed by coagulation factors.

What is Hemostasis?

Hemostasis is the name given to the process, which controls excessive bleeding after an injury or cut. A clot is formed to repair and close the hole in the blood vessel.

When a blood vessel faces an injury, platelets come together to form a plug. Clotting factors form a fibrin mesh that holds the platelets in position. This assists in healing the injury and preventing unnecessary loss of blood.

During surgery, doctors help patients with hemostasis so that blood loss can be controlled.

Why are coagulation tests performed?

Coagulation tests are performed to ascertain if the levels of your coagulation factors are normal. If the levels of the coagulation factors are low, it means poor clotting ability and therefore the risk of excessive bleeding during an injury. If the coagulation factor is high, it is connected to excessive formation of clots medically termed as thrombosis. This could cause blockage in the circulation system and lead to thromboembolism.

Coagulation factor tests can help find out if any of your coagulation factors has a problem and if you are suffering from a bleeding disorder. There are many types of bleeding disorders. Haemophilia is the most well-known of bleeding disorders and this is caused by either the absence or improper functioning of certain coagulation factors

Who needs coagulation tests?

You may be asked to undergo coagulation tests,

  • If your doctor doubts the presence of a clotting disorder. Clotting disorders can lead to excessive bleeding or formation of clots both of which are dangerous.
  • To evaluate various proteins in the blood and the manner in which they function.
  • To evaluate treatment measures for coagulation disorders, or assess and track the severity of factor deficiencies.
  • If your coagulation-screening test results tests are abnormal.
  • If someone in the family has a coagulation factor deficiency  or  bleeding  disorder.
  • Coagulation tests are conducted prior to surgery.
  • If you have exhibited certain symptoms of bleeding disorders such as
    • Pain and Swelling
    • Bruising very easily
    • Excessive bleeding after an injury
    • An unexplained blood clot
  • Victims of the following medical conditions also need to undergo coagulation tests :
    • Vitamin K deficiency
    • High clot formation called as thrombophilia
    • Liver disease
    • Patients who suffer from hemophilia, which means their bodies are unable to clot normally

Types of coagulation tests

Coagulation tests are many and below are some of the coagulation tests to evaluate your body’s ability to clot during an injury or trauma.

Platelet count

This test checks the platelet count in the blood.  Platelets in the blood assist in clotting during an injury.You may have an abnormally low number of platelets if you are on chemotherapy, take certain medications, or have had a massive blood transfusion. Deficiency of Vitamin K, leukemia and celiac disease can also result in a low platelet count. Anemia, primary thrombocythemia, or chronic myelogenous leukemia (CML) could cause an abnormally high number of platelets.

Fibrinogen level

This test evaluates the level of fibrinogen in the blood and is known with alternative titles such as hypofibrinogenemia test and factor 1. Liver produces fibrinogen , a protein. If the test results are abnormal, it could increase the risks of hemorrhage or excessive bleeding. This could also mean the onset of a condition called fibrinolysis. This test helps predict grave risks to pregnant women and the growing fetus,  such as the separation of the placenta from the uterine wall.

Prothrombin time (PT or PT-INR)

Prothrombin, produced by the liver is a protein that helps clotting. This test measures the time taken for the blood to clot. Doctors usually order the PT test along with another test called activated partial thromboplastin time (aPTT). The normal time for blood to clot is about 25 to 30 seconds. In case the patient is on blood thinners it may take a longer duration to clot.  There may be several reasons for abnormal prothrombin tests, which are liver disease, poor absorption and hemophilia.

Factor V assay

This is an investigation to check the levels of factor V,  an important substance that enables clotting. If the Factor V shows a severely low score, it could be indicative of a condition termed as primary fibrinolysis (a breakdown of clots). This factor V deficiency can also lead to disseminated intravascular coagulation (DIC).

Complete blood count (CBC)

Your healthcare provider will ask for a total blood count to check if you suffer from any other medical condition like a low platelet count or anemia that can hamper the ability to clot.

Thrombin time

Thrombin time measures how well fibrinogen is working. Certain medications disturb the normal clotting process. Genetic fibrinogen disorders , some cancers and disease of the liver can also cause abnormal coagulation test results.

Bleeding time

This test analyses how quickly small blood vessels in your skin close up and stop bleeding. It is performed differently than the other blood tests and is safe with very little chance of side effects. The test uses a blood pressure cuff that is positioned on the upper arm. This cuff is inflated. A number of tiny cuts are made on the lower arm. The cuff is deflated and removed, and the technician performing the test uses blotting paper in the cuts until the bleeding completely stops. Usually, bleeding lasts anywhere from one to nine minutes.

How are coagulation tests performed?

To perform coagulation tests, a blood sample is required.

A blood sample is drawn from a vein in your hand or arm using a small needle. A few milliliters of blood are needed and care must be taken that the blood sample tube is filled with the required level of blood for readings to be accurate. The sample drawn is collected in a test tube and is sent for evaluation to the laboratory.  This test can be performed by a lab technician or your healthcare professional.

Are there any risks involved in coagulation tests?

Coagulation tests are simple to perform and get done in a few minutes. There are no major risks involved with coagulation tests. In very rare cases patients report bruising, bleeding, or feeling faint after the blood sample is drawn. Recovery is quick and patients feel better within a few hours.

When can I get the results of coagulation tests?

The test report of coagulation tests may take a day to get ready after the blood sample is given for evaluation.

How do I interpret the test results?

The coagulation factors are reported usually as percentages and a 100% score in a test result is considered normal. This means the clotting function is normal. Each of the coagulation factors must be present in adequate quantity for clotting to take place, although the level is different for each factor.

A 20% test result is considered very low. If the score is low, it indicates impairment in the ability to clot. If the results show more than one clotting factor as deficient, this is normally due to an acquired condition.

How do the coagulation deficiencies reveal itself?

Deficiencies in coagulation factors can develop in several different ways and can be of varying severity. It can also be a permanent or temporary condition. Coagulation deficiencies can be genetic or acquired associated with other diseases. Those with acute factor deficiencies may experience excessive bleeding very early in life.

Few symptoms do show up sometimes during adulthood after trauma or surgery. It may reveal itself during PTT  (partial thromboplastin time (PTT) test) or prothrombin time (PT).

Coagulation factor levels do go up during inflammation, severe stress or chronic illness.

How much do coagulation tests cost?

The cost of the coagulation profile test can vary according to the diagnostic laboratory conducting the test as well as the location. The price of this test can range anywhere from INR 1750 to 1950.

Can coagulation tests be performed during pregnancy?

There are certain physiological changes to coagulation that occurs during pregnancy and this could lead to coagulation and platelet disorders, pregnancy associated fatty liver disease, von Willebrand disease, and few common factor deficiencies that can impact hemostasis.

Coagulation tests are performed in such cases to ensure safety during delivery and reduce risks of peripartum hemorrhage and epidural hematoma.

Are coagulation tests performed on children?

Doctors may ask children to undergo coagulation tests if the child has experienced abnormal bruising or bleeding. The tests may be needed in the event of a medical condition related to clotting. Tests are needed prior to a surgery or a procedure where the risk of bleeding is high. Coagulation tests are performed on children to track clotting levels among children who are on blood-thinning medications.

What else should I know?

It is possible to replace missing coagulation factors for acquired and inherited factor deficiencies. This is possible with fresh frozen plasma transfusion containing several coagulation factors. These types of treatments can be used during a bleeding event or to prevent uncontrolled bleeding during an invasive procedure or surgery.


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