Your major organs are spread across several body cavities, from your skull down to your pelvis. Most people searching this want a practical map: what’s on the left, what’s on the right, what’s up high behind the ribs, and what sits lower in the belly. Here’s a clear guide to where everything is and how your body organizes it all.
Organs in the Chest
The chest cavity (thoracic cavity) holds five organs: the heart, both lungs, the esophagus (the tube connecting your throat to your stomach), the trachea (your windpipe), and the thymus (a small gland involved in immune function). The cavity is divided into three sections. The two lungs each sit in their own space on either side of the chest, while the heart, esophagus, and trachea occupy the central compartment between them.
Your heart sits slightly left of center, roughly behind and just left of your breastbone. The left lung is a bit smaller than the right to make room for it. The right lung has three lobes; the left has two. Below all of these, the diaphragm forms a dome-shaped muscular floor that separates the chest from the abdomen. Every breath you take involves this muscle contracting and flattening downward.
Upper Abdomen: Right Side
The right upper part of your abdomen is dominated by the liver, the body’s largest internal organ. It sits mostly tucked up under the right side of your rib cage, covered by the diaphragm above it. The gallbladder, a small pouch that stores bile for digesting fat, hangs just beneath the liver. The head of the pancreas also sits in this area, along with the first part of the small intestine (the duodenum), which curves around it. A portion of the large intestine bends here as well, making a sharp turn called the hepatic flexure. The right kidney sits behind all of this, pressed against the back wall of the abdomen.
Upper Abdomen: Left Side
The left upper quadrant is home to the stomach, which tucks under the left side of the rib cage. Just behind and to the left of the stomach sits the spleen, an organ that filters blood and helps fight infection. The spleen lies against the diaphragm behind ribs 9 through 11 on the left side. The tail of the pancreas extends over to this side as well, since the pancreas is a long, narrow organ that stretches across the upper abdomen from right to left. Part of the large intestine curves through this area too, at a bend called the splenic flexure. The left kidney mirrors the right, sitting against the back body wall.
Lower Abdomen
The lower right side of your abdomen contains the appendix, a small finger-shaped pouch attached to the beginning of the large intestine. This is why appendicitis pain typically shows up in the lower right belly. The ascending colon (the part of the large intestine running upward) also lives on this side, along with loops of the small intestine.
On the lower left, the descending colon runs downward, connecting to the S-shaped sigmoid colon before reaching the rectum. More loops of the small intestine fill this area too. In people with female reproductive organs, an ovary and fallopian tube sit on each side of the lower abdomen, flanking the uterus. The bladder sits centrally, low in the pelvis, just behind the pubic bone.
Organs Hidden Behind the Abdomen
Several important organs don’t sit inside the main abdominal space at all. They’re tucked behind it, pressed against the back body wall in a region called the retroperitoneum. These include the kidneys, the adrenal glands (small hormone-producing glands sitting on top of each kidney), and the ureters (tubes that carry urine from the kidneys to the bladder). The pancreas and parts of the large intestine also migrated to this deeper position during fetal development. The body’s two largest blood vessels, the aorta and the main vein returning blood to the heart, run through this space as well.
Because these organs sit so deep, problems with them can cause back pain rather than the typical belly pain you might expect. Kidney pain, for example, is usually felt in the flank or mid-back rather than the front of the abdomen.
The Pelvic Cavity
Below the abdomen, the bony pelvis creates a protected space for the bladder, the lower portion of the large intestine, and the reproductive organs. In people with female anatomy, this includes the uterus, ovaries, and fallopian tubes. The pelvis in these individuals is wider and shallower, shaped to accommodate pregnancy and childbirth. In people with male anatomy, the prostate gland sits just below the bladder, and the pelvis is narrower and deeper.
The Brain and Spinal Cord
The brain fills the cranial cavity inside the skull, surrounded by three layers of protective membranes and cushioned by cerebrospinal fluid. The spinal cord extends downward from the brain through a channel formed by the stacked bones of the vertebral column. Both of these structures are completely enclosed in bone, making them the most heavily protected organs in the body.
How Your Body Keeps Organs in Place
Organs don’t just float freely inside you. A large, continuous fold of tissue called the mesentery anchors the intestines to the back wall of the abdomen. Different sections of it connect to the small intestine, the various parts of the colon, and the rectum. The mesentery also attaches to the liver, spleen, and pancreas. It holds everything stable while still allowing some movement, which is important because your intestines need to shift and contract as they digest food. Without it, the intestines could collapse, twist, or slide out of position.
Using Surface Landmarks to Find Organs
You can roughly locate your internal organs using a few external landmarks. The simplest system divides the abdomen into four quadrants by drawing an imaginary vertical line and a horizontal line through the belly button. Pain or tenderness in a specific quadrant helps narrow down which organ might be involved. The bottom edge of the rib cage marks the upper boundary of the abdominal cavity, while the hip bones mark the lower boundary. Your belly button sits roughly at the center.
The liver edge can sometimes be felt just below the right rib margin. The spleen, when it’s normal size, is usually not detectable from outside the body since it sits high under the left ribs. The kidneys sit roughly at the level of the lowest ribs in the back.
When Organs Are Reversed
In roughly 1 in 10,000 people, a genetic condition called situs inversus causes all the major organs to form as a mirror image of normal anatomy. The heart sits on the right side of the chest. The liver and gallbladder are on the left. The stomach and spleen move to the right. Most people with this condition live completely normal lives and may not even know about it until an imaging scan reveals the reversal. The main practical concern is that it can confuse the picture during medical emergencies, since pain from organs like the appendix will show up on the opposite side from what’s expected.