Haemorrhage
The escape of blood from a ruptured vessel, particularly when profuse.
What it means
Haemorrhage is the escape of blood from the circulation through a damaged vessel wall. From the Greek haima, blood, and rhegnynai, to burst forth.
It is described by site, and by whether the blood is visible:
- External — visible, from a wound or orifice
- Internal or concealed — within a body cavity or tissue, and potentially substantial before it becomes apparent
Specific terms describe bleeding from particular sites: haematemesis (vomiting blood), haemoptysis (coughing blood), melaena (black tarry stool from upper gastrointestinal bleeding), epistaxis (nosebleed), and subarachnoid haemorrhage (bleeding around the brain).
In practice
Used throughout emergency, surgical and obstetric records. "Postpartum haemorrhage" denotes excessive bleeding after childbirth and is a leading cause of maternal death worldwide.
A haematoma is a localised collection of blood that has escaped into tissue.
Why it matters
Significant blood loss produces a rising heart rate, falling blood pressure, pallor, sweating and confusion, in roughly that order. Younger people compensate well and may appear stable until the loss is considerable.
Coughing or vomiting blood, black tarry stools, or a sudden severe headache described as the worst ever experienced all require emergency assessment. Anyone taking anticoagulant medication who bleeds, or who sustains a head injury, warrants a lower threshold for urgent review.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026