Bleeding Disorders Diagnosis
It may be possible for your doctor to diagnose your bleeding disorder, its severity, and whether it is inherited or acquired based on your symptoms, risk factors, medical and family history, a physical exam, and blood tests.
It is not typical to screen for bleeding disorders unless you are having certain types of major surgery or have known risk factors.
To help diagnose a bleeding disorder, your doctor may ask you questions such as these:
- Do you have blood in your urine or stool?
- Does your family have a history of bleeding disorders, bleeding events, or blood clots?
- Do you have a history of miscarriage or postpartum bleeding?
- Do you have symptoms of other medical conditions associated with bleeding disorders?
- How long do your menstrual period lasts, and how many sanitary pads or tampons you use per day during your period?
- How often do you bruise or bleed, and how long does the bleeding last?
- What prescription or over-the-counter medicines, such as aspirin, do you take?
- Do your gums often bleed, or do you bleed a lot following dental procedures?
Your doctor will do a physical exam to look for signs of a bleeding disorder, such as bruising or petechiae. Your doctor may also look for signs of medical conditions that can cause bleeding disorders or signs of other medical conditions that can cause similar symptoms. Depending on the reason for your visit, the doctor may look for signs of bleeding-related complications, by looking for swelling and checking your blood pressure, heart rate, and breathing.
Diagnostic tests and procedures
To diagnose a bleeding disorder and whether it may be inherited or acquired, your doctor may order one or more of the following tests.
- A complete blood count (CBC) measures many different parts of your blood, such as the number of blood cells and platelets. If the number of platelets is too low, you may have a platelet disorder instead of a clotting factor disorder.
- A partial thromboplastin time (PTT) test, also called an activated PTT (aPTT), measures how long it takes blood to clot. It can help determine whether certain clotting factors are involved.
- A prothrombin time (PT) test is another test that measures how long it takes blood to clot. It measures clotting factors that the PTT test does not.
- A mixing test helps determine whether the bleeding disorder is caused by antibodies blocking the function of clotting factors, such as with autoimmune disorders or acquired hemophilia.
- Von Willebrand factor (vWF) tests measure the amount of von Willebrand factor, whether the factors are working correctly, or which type of VWD you have.
- Clotting factor tests, also called factor assays or a coagulation panel, helps determine whether certain clotting factors are missing or show up at lower levels than normal, which can indicate the type and severity of the bleeding disorder. For example, if you have very low levels of clotting factor VIII, you may have hemophilia A.
- A Bethesda test looks for antibodies to factor VIII or IX
- Factor XIII antigen and activity assays looks for factor XIII deficiency
- Genetic testing helps determine whether particular genes may be causing the bleeding disorder. Your doctor may refer you or your child to a specialist in genetic testing.
For some bleeding disorders, such as hemophilia, the clotting factor test can tell you how severe the disorder is. Below are possible results from testing for hemophilia A:
- Severe hemophilia A: <1% of factor VIII detected
- Moderate hemophilia A: 1% to 5% of normal factor VIII levels
- Mild hemophilia A: 6% to 50% of normal factor VIII levels
For hemophilia A, the amount of factor VIII is measured and compared to normal amounts. If you have mild hemophilia, you would have 50% or less of the factor VIII levels that a person without a bleeding disorder would have. If you have moderate hemophilia, you would have less than 6% of normal factor VIII levels. If you have severe hemophilia, there would be no detectable levels of factor VIII.
Tests for other medical conditions
Because bleeding can be caused by other medical conditions, your doctor may do tests or procedures to look for conditions that can cause acquired bleeding disorders, such as:
- A blood test called a liver panel, to measure substances in the blood that depend on liver function
- A lupus anticoagulant test, to look for signs of lupus
- A pregnancy test
- Procedures, such as a pelvic exam, Pap test, , or of the lining of the uterus, to look for signs of disorders that can cause heavy menstrual bleeding
If you are diagnosed with a bleeding disorder, your doctor may discuss your risk of passing your condition on to a future child.
Depending on your risk factors, your doctor may recommend screening your baby during your pregnancy using chorionic villus sampling (CVS). During CVS, the doctor threads a thin tube through the vagina to the placenta, where a tissue sample is collected using gentle suction. This test may be offered at 9 to 11 weeks to look for the hemophilia gene among women who are known hemophilia carriers, such as with hemophilia A or B. At a later stage during pregnancy, or after the baby is born, your doctor can do a blood test from the umbilical cord.