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What You Need to Know About Blood Clotting Disorders

Know the Basics|Symptoms|Risk Factors and Acquired Conditions|Diagnosis|Prevention|Conclusion
What You Need to Know About Blood Clotting Disorders

Know the Basics

What Are Blood Clotting Disorders?

When a person has a cut or suffers an injury, the body reacts to stop the bleeding in a process called coagulation. Proteins in the blood called clotting factors work together to create blood clots (thrombi), thickened tissue that slows blood loss. Once the cut or injury has healed, the body removes the clots by dissolving them.

The body has a system to prevent too much bleeding or clotting. When that balance is disrupted, excessive blood clotting or thrombosis may occur.

Excessive blood clotting disorders are a group of conditions characterized by unusual or excessive clotting (hypercoagulation). People with blood clotting disorders may have blood clots form too easily, sometimes even without injury, or blood clots that do not dissolve.

Clotting disorders are also referred to as:

  • Hypercoagulable states
  • Thromboembolic states
  • Thrombotic disorders
  • Thrombophilia

In people with blood clotting disorders, blood clots can travel to or form in the veins and arteries. Blood clots that form in blood vessels, called thrombi, can break off and travel through the bloodstream, limiting blood flow to another part of the body. Blood clotting disorders require timely, accurate diagnosis and appropriate treatment.

What Are the Possible Complications of Blood Clotting Disorders?

Venous Thromboembolism (VTE) is a condition that happens when a blood clot blocks a vein. Two kinds of this condition exist:

  • Deep vein thrombosis (DVT)

In DVT, clots usually develop in a vein embedded deep in the leg or, less commonly, in the pelvis or arm. These blood clots can block blood flow, resulting in symptoms such as swelling, pain, skin discoloration, and a feeling of warmth in the affected area. However, some people with DVT have no symptoms.

What You Should Know About Deep Vein Thrombosis

  • Pulmonary embolism (PE)

A pulmonary embolism is what happens when a blood clot breaks off and travels through the heart to the lungs, causing damage and blocking blood flow. This condition is extremely dangerous and requires rapid treatment. Symptoms of a pulmonary embolism include a rapid pulse, chest pain that worsens when breathing deeply or coughing, as well as sudden shortness of breath.

While the exact number of people who have DVT/PE is unknown, experts estimate that approximately 900,000 Americans could be affected each year.

Apart from the lungs, blood clots may also break off and block an artery in other organs such as the brain and kidneys. A blood clot in a vessel supplying blood to the brain can result in ischemic strokes, while a blood clot obstructing a vessel in the kidney can lead to kidney damage.

When a blood clot forms inside a blood vessel of the heart or if a thrombus travels through the bloodstream and blocks an artery of the heart, it can obstruct blood flow. Left untreated, coronary thrombosis can lead to a heart attack.

Pulmonary Embolism: The Danger of Blood Clots


What Are Symptoms of Blood Clotting Disorders?

Symptoms depend on where in the body the blood clot is located. They include:

  • Arm or Leg: Swelling/edema, warmth in one spot, and pain
  • Heart: Chest pain or heaviness, nausea, excessive sweating, dizziness, and shortness of breath
  • Lung: A rapid heartbeat, difficulty breathing, a fever, fainting spells, chest pain, and coughing up blood
  • Brain: Weakness, changes in sensation on one side of the body, seizures, dizziness, and changes in vision.
  • Abdomen: Severe abdominal pain, bloody stools and/or vomit, and diarrhea

Risk Factors and Acquired Conditions

What Puts You at Risk of Getting Blood Clotting Disorders?

Some people with blood clotting disorders are born with a genetic predisposition to form blood clots (inherited). For others, clotting disorders are linked to an acquired condition or other risk factors.

Inherited causes of excessive blood clotting include:

  • Factor V Leiden
  • Prothrombin gene mutation (G20210)
  • A deficiency in Protein S, Protein C, or antithrombin
  • Antiphospholipid antibody syndrome (APLS)
  • Hyperhomocysteinemia

Living with Hemophilia: Risks and Effects

Acquired causes that increase the risk of excessive clotting disorders include:

  • Cancer
  • Blood infections
  • Liver disease
  • Severe trauma
  • Some medications used to treat cancer, such as tamoxifen, bevacizumab, thalidomide and lenalidomide
  • Oral contraceptive pills & hormone replacement therapy
  • Heparin
  • Recent trauma or surgery
  • Smoking
  • Pregnancy


How to Get Diagnosed

A healthcare provider would typically look into a patient’s medical history to identify the factors that caused the blood clot. If the patient is showing symptoms, the healthcare provider may send them immediately for testing.

Tests that help in the diagnosis of blood clotting disorders include blood work. The D-dimer test is the most commonly used to rule out clotting episodes.

D-dimer is a protein fragment that is present in the blood when a blood clot breaks down. Higher-than-normal levels of D-dimer in the blood can mean the presence of a blood clot.

However, there are other conditions that cause elevated D-dimer levels. For this reason, other blood and imaging tests may be ordered. These include:

  • An ultrasound of the arm or leg (to identify DVT)
  • A CAT scan of the chest (to identify PE)
  • A CAT scan of the head and neck (for patients who have symptoms of stroke)
  • A phrothrombine time (PTT) test
  • An activated partial thromboplastin time (aPTT) test
  • A ventilation and perfusion (V/Q) scan
  • Magnetic resonance angiography (MRA)

Genetic tests can help diagnose inherited excessive blood clotting disorders. These include tests for:

  • Factor V Leiden
  • Antithrombin activity
  • Protein S activity
  • Protein C activity


Ways to Prevent Blood Clots

While some people were born more likely to develop blood clots than others, there are still some things you can do to prevent them. If your doctor prescribes blood thinners or other medication to prevent blood clots, be sure to take them as ordered.

Other steps you can take to prevent blood clots are:

  • Exercising Regularly

After surgery, illness, or other situation that requires prolonged bed rest, it’s best to get up and be active as soon as possible. Regular exercise improves blood circulation, which in turn helps prevent blood clots.

  • Making Lifestyle Changes

Lifestyle changes play an important role in reducing your risk for complications of blood clotting disorders. These include quitting smoking, losing weight (if overweight), and eating less salt.

  • Following Post-Surgery Instructions

Those who are confined to their beds for long periods due to surgery are at higher risk for developing a blood clot. Following your care team’s instructions in the hospital and at home can help prevent blood clot formation. These instructions may include taking blood thinners, taking short walks, and wearing sequential compression device (SCDs).


While some people are genetically predisposed to blood clotting disorders, blood clots can happen to anyone at any age. Medical care and lifestyle changes are essential in decreasing the risk of a blood clot. Proper care and preventative measures can help prevent a blood clot from getting larger or breaking loose. It can also help reduce the odds of developing more blood clots in the future.

Learn more about Blood Disorders here.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Symptoms and Diagnosis of Venous Thromboembolism (VTE), https://www.heart.org/en/health-topics/venous-thromboembolism/symptoms-and-diagnosis-of-venous-thromboembolism-vte, Accessed Aug. 11, 2020

Deep Vein Thrombosis: Myths vs. Facts, https://www.hematology.org/education/patients/blood-disorders/deep-vein-thrombosis, Accessed Aug. 11, 2020

Renal vein thrombosis, https://stanfordhealthcare.org/medical-conditions/blood-heart-circulation/renal-vascular-disease/types/renal-vein-thrombosis.html, Accessed Aug. 11, 2020

THROMBOSIS / CORONARY THROMBOSIS, https://web.archive.org/web/20040427120227/http://www.cts.usc.edu/zglossary-thrombosis.html, Accessed Aug. 11, 2020

Blood Clots in Veins, Heart and Lungs, https://www.yalemedicine.org/conditions/blood-clots-in-veins-heart-and-lungs/, Accessed Aug. 11, 2020

Post-Thrombotic Syndrome, https://www.cedars-sinai.org/health-library/diseases-and-conditions/p/post-thrombotic-syndrome.html, Accessed Aug. 11, 2020

Deep Vein Thrombosis (DVT), https://my.clevelandclinic.org/health/diseases/16911-deep-vein-thrombosis-dvt, Accessed Aug. 11, 2020

Factor V Leiden thrombophilia, https://ghr.nlm.nih.gov/condition/factor-v-leiden-thrombophilia#:~:text=Factor%20V%20Leiden%20thrombophilia%20is,that%20can%20block%20blood%20vessels., Accessed Aug. 11, 2020

Prothrombin thrombophilia, https://ghr.nlm.nih.gov/condition/prothrombin-thrombophilia, Accessed Aug. 11, 2020

Prothrombin time test, https://www.mayoclinic.org/tests-procedures/prothrombin-time/about/pac-20384661#:~:text=A%20prothrombin%20time%20test%20measures,help%20it%20to%20clot%20appropriately., Accessed Aug. 11, 2020

Blood Clotting Disorders (Hypercoagulable States): Diagnosis and Tests, https://my.clevelandclinic.org/health/diseases/16788-blood-clotting-disorders-hypercoagulable-states/diagnosis-and-tests, Accessed Aug. 11, 2020

Blood Clots, https://www.radiologyinfo.org/en/info.cfm?pg=bloodclot, Accessed Aug. 11, 2020

Are you at risk for developing at blood clot?, https://www.med.unc.edu/htcenter/patient-care/clotting-disorders/blood-clot-education-1/are-you-at-risk-for-developing-at-blood-clot/, Accessed Aug. 11, 2020


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Written by Kip Soliva Updated Jun 03
Medically reviewed by Jobelle Ann Dela Cruz Bigalbal, M.D.