ABC of clinical haematology: Bleeding disorders, thrombosis, and anticoagulationBMJ 1997; 314 doi: https://doi.org/10.1136/bmj.314.7086.1026 (Published 05 April 1997) Cite this as: BMJ 1997;314:1026
- K K Hampton,
- F E Preston
Blood within the vascular tree remains fluid throughout life, but if a blood vessel is damaged, blood will clot in a rapid localised response. Failure of clotting leads to bleeding disorders; thrombosis is inappropriate clotting within blood vessels. The haemostatic system is complex, and many congenital and acquired conditions can disturb its correct functioning.
History in bleeding disorders
Abnormal bleeding from cuts and abrasions
Bleeding after dental extraction
Bleeding during childbirth
Bleeding during surgery
Previous anaemia and transfusions
Personal and family history is as important as laboratory investigation in assessing bleeding disorders. Easy bruising, nose bleeds (especially in children), and menorrhagia are common and do not necessarily signify a haemostatic defect unless they are persistent and severe. Small bruises on the limbs in response to minor trauma and simple easy bruising are especially common in elderly people and those receiving long term corticosteroids.
Large bruises after minimal trauma and on the trunk may indicate an important haemostatic defect. Abnormally prolonged bleeding from minor cuts and scratches and delayed recurrence of bleeding are also important, as is gum bleeding if there is no gingival disease and if it is unrelated to the trauma of brushing. Repeated nose bleeds lasting more than 10 minutes despite compression suggest a local cause or an underlying bleeding disorder.
Persistent menorrhagia sufficient to cause iron deficiency anaemia may indicate a bleeding disorder if no structural uterine abnormality is present
The haemostatic response to previous haemostatic challenges is informative, especially in mild conditions when spontaneous bleeding is rare. A history of excessive bleeding or recurrence of bleeding after dental extractions, circumcision, tonsillectomy, other previous surgical operations, and childbirth should be sought, as should a history of unexplained anaemia, gastrointestinal bleeding without the demonstration of a cause, and previous blood transfusion.