What Organs Are on the Right Side of the Body?

The right side of your body houses several major organs, including the bulk of the liver, the gallbladder, the right lung, the appendix, the right kidney and adrenal gland, and significant portions of the intestinal tract. Some structures you might think of as “central,” like the heart, also have functionally distinct right-side components. The arrangement is not random: it was established during the first few weeks of embryonic development by a remarkably elegant process that occasionally goes wrong in ways that flip the entire map.

The Right Lung

Your right lung is larger than your left, and the reason is straightforward: the heart sits slightly left of center, crowding the left lung and reducing its volume. To compensate, the right lung has three lobes while the left has only two. That extra lobe gives the right lung roughly 55 to 60 percent of your total lung capacity. Each lobe is separated by tissue boundaries called fissures, and a systematic review of anatomical studies found that these fissures are frequently incomplete or variable, with anatomical variations showing up in about 55 percent of right lungs compared to 33 percent of left lungs.¹ Surgeons care about these variations because they affect how lung tissue can be removed or resected, but for day-to-day breathing, even lungs with unusual fissure patterns work just fine.

The Liver and Gallbladder

The liver is the largest solid organ in the body, and the vast majority of it sits in the upper right part of your abdomen, tucked beneath the diaphragm and shielded by the lower ribs. It is divided into lobes, and the right lobe is by far the largest, handling most of the liver’s metabolic and detoxification work.² It filters blood arriving from the digestive tract, metabolizes drugs and toxins, produces bile for fat digestion, stores glycogen for energy, and manufactures proteins your blood needs to clot.

Nestled just beneath the right lobe of the liver is the gallbladder, a small pear-shaped pouch that stores and concentrates bile between meals. When you eat something fatty, the gallbladder contracts and squeezes bile into the small intestine through a series of ducts. Gallstones, which form when bile components crystallize, are one of the most common causes of sharp pain in the upper right abdomen. This area, known clinically as the right upper quadrant, generates a broad range of possible diagnoses when something hurts there, from gallbladder inflammation to liver disease to problems with neighboring structures.³

The liver’s internal anatomy is more complex than a simple left-right split might suggest. Surgeons describe it using a segmental system based on how blood vessels and bile ducts branch through the tissue. Operations on the right anterior sector of the liver remain among the more challenging procedures in abdominal surgery, with substantial operating times and blood loss.⁴ That complexity is part of why liver tumors or injuries on the right side sometimes require highly specialized surgical planning.

The Appendix, Cecum, and Ascending Colon

In the lower right part of your abdomen sits the cecum, a pouch-like beginning of the large intestine where the small intestine empties into it. Attached to the cecum is the appendix, a narrow, finger-like tube whose exact biological purpose is still debated, though it likely plays a role in immune function and may serve as a reservoir for beneficial gut bacteria. The ascending colon then travels upward from the cecum along the right side of the abdomen before making a sharp turn (the hepatic flexure, named because it bends near the liver) and crossing to the left as the transverse colon.

When the appendix becomes inflamed, the resulting appendicitis typically produces pain that starts vaguely around the navel and then migrates to a spot in the lower right abdomen. That location, called McBurney’s point, is roughly a third of the way from the hip bone to the navel, and tenderness there remains a key finding when doctors evaluate abdominal pain.⁵ The catch is that the appendix does not always sit in its textbook position. The cecum itself can be mobile, and the appendix can point in various directions or even end up in unusual locations, which can make the pain pattern misleading.⁶ In those cases, imaging becomes essential because the classic signs on physical exam may not match up.

The Right Kidney and Adrenal Gland

You have two kidneys, one on each side of your spine in the back of the abdominal cavity, and the right kidney sits slightly lower than the left. That asymmetry exists because the liver, sitting above it, pushes it downward. Each kidney filters blood, removes waste, regulates fluid balance, and produces urine. Perched on top of each kidney like a small cap is an adrenal gland. The right adrenal gland is roughly triangular and sits close to the inferior vena cava, the large vein that returns blood to the heart from the lower body. That proximity to a major blood vessel makes right adrenal surgery somewhat trickier than left.

Kidney stones on the right side produce pain that often radiates from the flank toward the groin, and this pain can sometimes be confused with appendicitis or gallbladder trouble depending on the stone’s exact location. The overlap with other right-sided organ problems is one reason clinicians rely heavily on imaging and lab tests rather than pain location alone when working through a diagnosis.

Right-Side Structures in Circulation and Lymphatics

The heart is often described as a left-sided organ, and its overall mass does lean to the left, but the right side of the heart is a complete pumping system in its own right. The right atrium receives deoxygenated blood returning from the body through the superior and inferior vena cava. That blood then passes into the right ventricle, which pumps it to the lungs for oxygen pickup. This right-heart circuit handles the same volume of blood as the left side but operates at much lower pressure, which is why the right ventricle’s muscular wall is thinner.

On the lymphatic side, the right lymphatic duct is a small vessel that drains lymph fluid from the right arm, the right side of the head and neck, and the right half of the chest. It empties into the venous system near the junction of the right internal jugular and subclavian veins. The rest of the body’s lymph, which is the large majority, drains through the thoracic duct on the left side. This asymmetry is clinically relevant in conditions like lymphedema after surgery: which arm or side swells depends partly on which lymphatic channels were disrupted.

The Right Side of the Reproductive System

Both men and women have paired reproductive structures that place one organ on each side. Women have a right ovary and a right fallopian tube, which sit in the lower right pelvis. Right-sided ovarian cysts or ectopic pregnancies in the right fallopian tube can mimic appendicitis closely enough that distinguishing them is a well-known diagnostic puzzle in emergency medicine. Men have a right testicle, which usually hangs slightly higher than the left, along with associated structures like the right epididymis and vas deferens.

How Referred Pain Complicates the Picture

Organs on the right side do not always hurt where you would expect. One of the classic examples involves the diaphragm, the large muscle separating the chest from the abdomen. The phrenic nerve, which controls the diaphragm, also carries sensory fibers from the diaphragm’s surface. Irritation of the underside of the right diaphragm, whether from blood, air, or inflammation after surgery, can produce pain that the brain interprets as coming from the right shoulder. This type of referred shoulder pain occurs in roughly a third to over half of patients recovering from abdominal or thoracic surgery.⁷

Gallbladder pain similarly radiates in ways that can be misleading. A gallbladder attack may produce pain that wraps around from the upper right abdomen to the back or right shoulder blade. Liver problems can cause a dull ache throughout the right upper quadrant that is hard to pin down. And kidney stones on the right side send waves of pain from the flank to the groin that can be mistaken for problems with the intestine or reproductive organs. The lesson is that the location where you feel pain and the organ producing it are often not in the same place, especially on the right side where so many organs are packed closely together.

When Left and Right Are Reversed

In a rare condition called situs inversus totalis, every major organ is flipped to the mirror-image position: the liver and gallbladder sit on the left, the spleen and stomach on the right, and the heart’s apex points to the right instead of the left.⁸ People with this condition often live completely normal lives and may not discover the reversal until they have imaging done for an unrelated reason. One study investigated whether this full-body mirror reversal extends to the brain and found that it was worth asking, since asymmetries in brain structure and function are well established in the general population.⁹

More complicated and more medically serious is heterotaxy syndrome, where the reversal is incomplete or inconsistent. Instead of a clean mirror flip, some organs end up on the wrong side while others stay put, and some structures that should be asymmetric develop as if both sides of the body were identical. This manifests as abnormal arrangement of organs across the left-right axis and often includes significant heart defects.¹⁰ In one pattern called right isomerism, the body essentially builds two right sides: both lungs have three lobes, the spleen is absent (since the spleen is a “left side” organ), and the heart has two right-type atrial appendages. In left isomerism, the pattern reverses, and patients may end up with multiple small spleens instead of one. A study of patients with heterotaxy found that the classic textbook patterns of right or left isomerism were breached in about one in five cases, with organs at different levels of the body showing mismatched sidedness.¹¹

Heterotaxy also affects the gastrointestinal tract. When the midgut does not complete its normal rotation during fetal development, the intestines can end up in atypical positions. In malrotation, the small bowel loops may cluster on the right while the appendix and ascending colon end up on the left, essentially scrambling the abdominal map that surgeons depend on.¹² This is why radiologists and surgeons treating anyone with known heterotaxy or situs inversus have to verify organ positions on imaging before making assumptions about what hurts and why.

How the Embryo Decides Which Side Gets What

The fact that the liver reliably ends up on the right, the spleen on the left, and the heart tilted leftward is the result of a symmetry-breaking event that happens very early in development. In mammals, a small pit on the underside of the embryo called the ventral node contains two types of tiny hair-like structures called cilia. Motile cilia at the center of the node spin in a clockwise direction, but because they are tilted toward the back of the embryo, their rotation generates a net leftward flow of fluid across the node’s surface.¹³ This leftward flow, called nodal flow, is the first physical event that makes left different from right.

A second population of immotile cilia, positioned around the edges of the node, detects this flow. The signal they receive, whether chemical or mechanical, triggers a cascade of gene activity that is different on the left side than on the right.¹⁴ That molecular difference cascades outward, telling developing organs where to position themselves, which direction to loop, and how to shape their internal structures. The heart tube, for instance, loops to the right in normal development; the gut tube rotates in a specific direction; the liver bud expands preferentially to the right.

When the genes governing cilia structure or motility are mutated, nodal flow is disrupted. In some cases this produces a clean reversal (situs inversus), and in others it produces the chaotic mismatches of heterotaxy. The variety of outcomes reflects how many separate downstream steps depend on that initial leftward flow: disrupt the signal early and everything flips symmetrically; disrupt it partially and individual organs may receive conflicting instructions. Researchers have identified dozens of genes involved in this process across vertebrate species, and mutations in many of them have been linked to human laterality disorders and associated heart defects.¹⁵

Organs That Straddle the Midline

Several organs are not cleanly on one side or the other, and it is worth knowing which ones extend into the right half of your body even though they are often described as central structures. The pancreas, usually thought of as sitting behind the stomach, has its head tucked into the C-shaped curve of the duodenum on the right side while its tail stretches leftward toward the spleen. The duodenum itself, the first segment of the small intestine, loops through the right upper quadrant. The inferior vena cava runs along the right side of the spine, collecting blood from the lower body and delivering it to the right atrium. The abdominal aorta runs along the left side of the spine, so the two great vessels are not symmetrically placed: one favors the right, the other the left.

The stomach and spleen, by contrast, are firmly left-sided in typical anatomy, which is why pain in the upper left abdomen raises a different set of diagnostic questions than pain on the right. The bladder sits centrally in the pelvis, and the uterus in women is roughly midline, though it tilts slightly in most people and ovarian pathology on either side can shift the perceived location of pelvic pain.

Understanding which organs live where is not just an anatomy-class exercise. When something hurts, the quadrant it occupies is often the first clue a clinician uses to narrow a diagnosis. Right upper quadrant pain points toward the liver, gallbladder, or right kidney. Right lower quadrant pain points toward the appendix, cecum, right ovary, or right ureter. Knowing the standard map, and knowing when that map might be unreliable because of anatomical variation or congenital reversal, is the foundation of every abdominal exam.