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What Are Coagulation Studies?

Medically Reviewed by Dan Brennan, MD on May 17, 2021

Coagulation studies help you understand blood disorders, so you can pursue treatment options to improve your blood’s ability to form clots.

How Blood Coagulation Works

Blood coagulation, or blood clotting, is a process that includes multiple factors, all produced by your liver and blood vessels. Each factor contributes to your clotting ability. One or more factors may not work correctly.

For example, one factor impacting your blood’s clotting ability is a protein that circulates through your bloodstream. In some cases, you may have too many of these proteins, making your blood clot too easily. A lack of these proteins can lead to unexplained bleeding that isn’t easily stopped.

Most coagulation tests look for activity within your blood rather than specific proteins. While it's easy to determine the amount of coagulation protein in your bloodstream, the test results won’t show if the proteins work correctly. A blood activity test shows the actual function of your blood.

Your blood needs to clot to protect your body from too much blood loss following an injury. When you get hurt, your coagulation system activates and plugs leaking blood vessels to stop active bleeding.‌

Your body’s blood clotting function is dynamic. Once a clot successfully forms, your body begins breaking it down. This process is called fibrinolysis. Eventually, your body dissolves the clot.

If you’ve ever sustained a cut or scrape, you’ve probably noticed a thick patch of blood that forms and dries at the site of the wound. This is a blood clot. It stays in place until the skin heals completely.

If you have a bleeding disorder, your blood doesn’t clot the way it should. Many blood disorders are hereditary, but some form after birth. If you have signs of a bleeding disorder, your doctor can test for specific factors to determine which treatment is right for your specific diagnosis.‌

Coagulation Studies

When you sustain damage, your body depends on specific interactions between the plasma–based coagulation factors, blood platelets, and the endothelium of your blood vessels. Coagulation studies measure these interactions in your blood. Specific types of coagulation tests include:

  • Prothrombin time (PT)
  • Activated partial thromboplastin time (aPTT)‌
  • Thrombin time (TT)

These studies help make sense of unexplained bleeding. They may also provide answers about hereditary risks for blood clotting disorders. However, they won’t predict the severity of a bleed in the future. Once results come back from a testing lab, your blood technician reviews the results with you to provide answers.

Reasons for a Coagulation Study

The obvious reason for a coagulation study is unexplained bleeding or bleeding that doesn’t stop. However, sometimes other health conditions lead to poor blood coagulation. Coagulation studies may help diagnose liver disease or a vitamin K deficiency.‌

If you’re taking a medicine to thin your blood, a coagulation study provides results on how much your blood is affected by the medication. Other reasons for a coagulation study include:

  • An injury that causes severe blood loss
  • Bruising easily
  • Persistent swelling
  • Unexplained pain and stiffness
  • Blood clot

Understanding Coagulation Test Results

If your activity report is normal, that means your blood exhibits normal clotting function. Low activity means you probably bleed easily, while high function means you probably clot easily.‌

For each factor, 100% is considered normal. As your percentage goes up or down, your condition worsens. In some cases, a coagulation study indicates that something is temporarily affecting your blood’s ability to clot. This is good news because it means you may be able to take steps to address concerns.‌

When more than one of your blood’s clotting factors is negatively impacted, your condition is most likely hereditary. Because this may be caused by a chronic health condition, your doctor may suggest additional tests.

Health conditions that decrease clotting factors in your blood include:

  • Liver disease
  • Cancer
  • Venom from a snake bite
  • Inability to absorb fat
  • Vitamin K deficiency
  • Medications, like Warfarin
  • Blood transfusions 

It's important to keep your blood’s clotting ability in mind when you're considering medical procedures where blood clotting is important, like a dental excision. Talk to your doctor before undergoing any procedures and ensure other medical professionals know about your condition in advance.

Understanding the impact of hereditary disorders. Hemophilia A and Hemophilia B are commonly passed down through genetics. If you have a family member with one of these blood disorders, you may have it, too.‌

These disorders are linked to the X chromosome in your genetic makeup, which is why men are more likely to suffer from the conditions. Women may carry the genes, passing them down to daughters and sons without ever showing symptoms of the disease.

Show Sources

SOURCES:

AACC: “Coagulation Tests.”

Lab Tests Online: “Coagulation Factors.”

Medline Plus: “Coagulation Factor Tests.”

Merck Manuals: “Coagulation Factors.”

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