Haemorrhage 

Definition: 

Hemorrhage is extravasation of blood outside the blood vessel. 

 Causes:

•  Physical trauma   – Stabbing 

- Stick injury 

- Gunshot 

- Motor vehicle accident 

 •  Inadequacies in blood clotting which can be due to: 

A.  Too few or poorly functioning platelets (i.e. qualitative & quantitative defect of platelets) 

B.  Missing or low amount of clotting factors 

E.g. Low levels of prothrombin, fibrinogen & other precursors. 

Inadequate vitamin K leads to clotting factor deficiency because this vitamin is important in the synthesis of the clotting factors by the liver.

 Terminology:

  1) Haemorrhage enclosed within a tissue or a cavity is knownas hematoma. 

2) Minute 1-2 mm hemorrhages occurring in the skin, mucosal membrane, or serosal surface are called petechiae. 

3) Slightly > 3mm hemorrhage occurring in the skin is referred to as purpura. 

4) Larger than 1-2cm subcutaneous hematoma is called eccymosis (bruises). It is typical after trauma. 

Effects of haemorrhage: depend on the rate and amount of blood loss:

•  If > 20% the total blood volume is rapidly lost from the body, it may lead to hypovolumic shock & death.

•  Chronic loss of blood leads to anaemia.

References

Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.