Normal blood clotting, called coagulation, is a complex process in which blood cells (called platelets) and different proteins in the blood (called clotting or coagulation factors) clump together to heal broken blood vessels and control bleeding. Coagulopathies (disorders of the blood clotting system) occur when clotting factors are missing or damaged, or when the number or function of the platelets is impaired. Coagulopathies include bleeding disorders (hemorrhagic disorders) and clotting disorders (thrombotic disorders or hypercoagulable states). In bleeding disorders, the blood does not clot fast enough, resulting in prolonged or excessive bleeding. In clotting disorders, the blood clots too quickly and can result in clots in the veins or arteries.

Causes

Some coagulopathies are inherited, while others develop because of illness or treatment with certain drugs. Causes of bleeding problems include the following:

• Inherited disorders, such as hemophilia (a disease where the blood doesn’t clot normally) and von Willebrand’s disease (a bleeding disorder where clotting factors are missing or do not work well)
  
• Vitamin K deficiency
  
  
• Liver cancer
  
  
• Cancers that metastasize (spread) to the liver, including breast, colon, and pancreatic cancer
  
  
• Other liver disorders, including hepatitis (an infection of the liver) and liver cirrhosis (scarring of the liver)
  
  
• Long-term use of powerful antibiotics or anticoagulant medications (blood thinners)
  
  
• Angiogenesis inhibitors (anticancer drugs that prevent the growth and development of new blood vessels), such as bevacizumab (Avastin) and sorafenib (Nexavar)
  
  
• Thrombocytopenia, an unusually low level of blood platelets caused by some cancers (leukemia and lymphoma), some chemotherapy, and other medications
  
  
• Anemia, an unusually low level of red blood cells
  
  
• Other disorders unrelated to cancer

Causes of clotting problems include the following:

• Inherited conditions, including:
• • Factor V Leiden disorder (a gene that is needed for blood clotting; people with disorders of this gene have a greater risk of clotting problems),
    
    
  • Protein C deficiency (a disorder that increases the risk of blood clots),
    
    
  • Antithrombin III deficiency (a disorder that can cause abnormal blood clots)
    
    
• Adenocarcinoma (type of cancer that begins in cells that line internal organs), including those of the small bowel, esophagus, and uterus.
  
  
• Myeloproliferative disorders (disorders resulting in an overproduction of blood cells, such as some types of leukemia)
  
  
• Use of birth control pills or tamoxifen (Nolvadex)
  
  
• Surgery
  
  
• Other disorders unrelated to cancer, including lupus

Symptoms

People with bleeding disorders may experience the following symptoms:

• Cuts that bleed excessively
  
  
• Unexpected bruising
  
  
• Petechia (small purple or red spots under the skin)
  
  
• Menstrual periods that are heavier or longer than usual
  
  
• Blood in the vomit, often resembling coffee grounds
  
  
• Black or bloody bowel movements, or reddish or pinkish urine
  
  
• Dizziness, headaches, or changes in vision
  
  
• Joint pain
  
  
• Gum bleeding

The most common symptom of a clotting disorder is a blood clot called a thrombosis. A thrombosis can occur in superficial veins (veins that are close to the surface of the skin), deep veins, or arteries. A superficial thrombosis is not dangerous but can cause varicose veins. A deep vein thrombosis (DVT) can be life-threatening if pieces of the clot break off and lodge in the lungs, called a pulmonary embolism. A DVT is most common in the legs, and symptoms include pain, redness, and swelling. Symptoms of a pulmonary embolism include chest pain and shortness of breath. An arterial thrombosis is extremely dangerous and can cause a heart attack, stroke, or organ damage.

Diagnosis

Bleeding and clotting disorders are diagnosed by medical history, physical examination, and laboratory tests. Blood tests include a complete blood count (CBC), prothrombin time (PT or INR), activated partial thromboplastin time (APTT), platelet count, tests to check the speed of blood clotting, and tests to check for blood protein deficiencies.

Treatment

Treatment of bleeding and clotting disorders depends on the underlying cause. When possible, underlying disorders such as cancer or liver disease are treated. Additional treatments include:

• Vitamin K injections
  
  
• Anticoagulant (blood thinner) medications, such as warfarin (Coumadin), heparin (multiple trade names), enoxaparin (Lovenox), dalteparin (Fragmin), and aspirin
  
  
• Clotting factor products or blood clotting agents
  
  
• Blood plasma or platelet transfusions

Other medications, including hydroxyurea (Droxia or Hydrea), and oprelvekin (Neumega) to treat platelet problems

More Information

What to Know: ASCO's Guideline on Preventing and Treating Blood Clots

Donating Blood and Platelets

Managing Side Effects

Last Updated: April 09, 2009