Abdominal Cavity

by S. Serkan Sezer MD

The abdominal cavity is the hollow space inside your body that sits below the chest. It’s the internal “room” that holds and protects many of your vital organs — essentially the inside of what people call the belly.

It is separated from the chest cavity above it by the diaphragm, the dome-shaped breathing muscle. Below, it opens into the pelvic cavity. So you can think of it as the large internal space between the breathing muscle and the pelvis.

What it holds

The abdominal cavity contains and cushions several organs essential for digestion and filtering, including:

  • Stomach
  • Small and large intestines
  • Liver
  • Gallbladder
  • Pancreas
  • Spleen
  • Kidneys

These organs are not loose inside the cavity — they are held in place and protected by a smooth membrane lining called the peritoneum, which also lets them glide against one another as you move and breathe.

Why it matters

The cavity does more than just store organs. Its walls — made of muscle (including the abdominal muscles) and supported by the spine at the back — protect the soft organs inside from injury. The space also allows the organs room to expand and work, such as when the stomach fills after a meal or the intestines move food along.

In medicine, the abdominal cavity is important for many procedures and diagnoses. For example, fluid can sometimes build up inside it (a condition called ascites), and surgeons frequently operate within it — increasingly through small keyhole incisions in a technique called laparoscopy.

A note on related terms

The abdominal cavity is part of a larger continuous space sometimes called the abdominopelvic cavity, which combines the abdominal cavity with the pelvic cavity below it. You may also encounter the term peritoneal cavity, which refers more precisely to the space lined by the peritoneum membrane.

Disclaimer

This content is for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Conditions affecting the abdominal cavity and its organs can range from minor to serious. If you have concerns about abdominal symptoms — such as pain, swelling, or bloating — consult a qualified healthcare professional, or in an emergency, call your local emergency number.