Vein · Heart & chest
Vena Cava
The vena cava is the body's largest vein — actually two great veins that return oxygen-poor blood from the body back to the heart, ready to be sent to the lungs.
What it is
The vena cava is made of two large veins: the superior vena cava (from the upper body) and the inferior vena cava (from the lower body), both emptying into the heart.
Where it runs
The superior vena cava is above the heart draining the head, neck and arms; the inferior vena cava is below it draining the trunk and legs.
What it does
Return deoxygenated blood from the whole body back to the right side of the heart, which then pumps it to the lungs to collect oxygen.
When things go wrong
Common problems affecting the vena cava
- Blood clots (deep vein thrombosis can extend towards it)
- Compression by tumours (superior vena cava obstruction)
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. Sudden severe chest, back or abdominal pain, sudden breathlessness, or stroke symptoms (FAST) are emergencies — call 999.
Did you know?
An interesting fact
The inferior vena cava is the largest vein in the body, carrying blood from everything below the heart back up to it.
Answers
Vena Cava: frequently asked questions
What does the vena cava do?
The vena cava returns oxygen-poor blood from the body to the heart, which then sends it to the lungs to pick up oxygen.
Related vessels
Other vein
Sources
Where this is drawn from
- NHS — Blood and the circulatory system
- Gray's Anatomy for Students
- British Heart Foundation — how the heart works
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