What is the largest internal organ?
General information only. This article explains the basics and is not medical advice. For anything about your own health, talk to a doctor or other qualified professional.
Quick answer
The liver is the largest internal organ in the human body, weighing about 1.4–1.6 kg (3–3.5 lb) in adults. It sits in the upper right of the abdomen, under the ribs. The skin is the largest organ overall, but it’s on the outside.
Largest organs in the body
| Organ | Approx. weight (adult) |
|---|---|
| Skin (external) | ~3.5–4.5 kg |
| Liver | ~1.5 kg |
| Brain | ~1.3–1.4 kg |
| Lungs (pair) | ~1.3 kg |
| Heart | ~0.3 kg |
| Kidneys (pair) | ~0.3 kg |
What the liver does
The liver performs hundreds of jobs. Some of the most important:
- Filters blood, breaking down toxins, alcohol and medicines
- Makes bile, which helps digest fats
- Stores energy as glycogen and releases sugar when needed
- Stores vitamins and iron
- Makes proteins that help blood clot
- Processes nutrients absorbed from the gut
About 1.4 liters of blood flow through the liver every minute.
An organ that regrows
The liver has a remarkable ability to regenerate. If part of it is removed, the remaining liver can grow back to nearly full size within weeks. This makes it possible for a living person to donate part of their liver for a transplant.
Keeping it healthy
Health services highlight a few general habits for liver health: drinking alcohol within recommended limits, keeping to a healthy weight, and getting vaccinated against hepatitis where recommended. Liver problems often cause few symptoms early on, so anyone with concerns should talk to a doctor.
For other body records, see the smallest bone. Insulin comes from a neighboring organ, the pancreas.
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