Several organs sit directly against or near your back, even though you might think of them as “abdominal” organs. The kidneys are the most well-known, but your lungs, pancreas, adrenal glands, and parts of the large blood vessels all occupy space close to your spine. Understanding what’s back there helps explain why pain in your back isn’t always about muscles or bones.
Kidneys
Your two kidneys are the organs most closely associated with the back. They sit in the retroperitoneal space, meaning they’re behind the lining of your abdominal cavity, tucked against the muscles on either side of your spine. Specifically, they rest between the level of your lowest rib and the third lumbar vertebra, roughly in the area you’d touch if you placed your hands on your lower back just below your ribcage. The left kidney typically sits slightly higher than the right, because the liver pushes the right one down a bit.
Because of their position, kidney problems are one of the most common organ-related causes of back pain. Kidney pain is usually felt in the flank, the area on either side of the spine beneath the ribs and above the hips. Unlike muscular back pain, kidney pain doesn’t get better or worse when you change positions. It tends to stay constant and is often accompanied by other symptoms: nausea, fever, cloudy or bloody urine, painful urination, or a frequent urge to go. Kidney stones, infections, and swelling can all produce this kind of deep, steady flank pain.
Adrenal Glands
Sitting on top of each kidney like a small cap, the adrenal glands are triangular organs roughly the size of your thumb. They produce hormones that regulate blood pressure, metabolism, your stress response, and your sleep-wake cycle. The outer layer produces cortisol (which manages energy and inflammation) and aldosterone (which controls blood pressure by balancing sodium and potassium). The inner core produces adrenaline and noradrenaline, the hormones behind the fight-or-flight response that speed your heart rate and sharpen your focus during emergencies.
Because the adrenal glands are so small and deeply embedded, they rarely cause noticeable back pain on their own. But tumors or other adrenal conditions can sometimes produce vague discomfort in the flank area alongside hormonal symptoms like unexplained weight changes, high blood pressure, or fatigue.
Lungs
People often think of the lungs as being in the front of the chest, but a large portion of your lung tissue extends into the back. Most of each lung’s lower lobe is accessible only from the posterior side of the body, reaching down to about the level of the 10th rib near the spine. That’s why doctors listen to your breathing from your back during a physical exam: they’re checking the lower lobes, which are the areas most prone to fluid buildup and pneumonia.
Lung conditions like pneumonia, pleurisy (inflammation of the lining around the lungs), blood clots, or a collapsed lung can all cause pain that feels like it’s coming from the upper or mid-back. This pain often worsens with deep breathing or coughing, which is a key distinction from muscle strain.
Pancreas
The pancreas is a long, narrow organ that sits deep in the abdomen, sandwiched between the stomach and the spine. Its tail extends toward the left side of the body near the spleen. Because part of the pancreas rests directly against the spine, inflammation of the pancreas (pancreatitis) frequently causes pain that bores straight through to the mid-back. This pain is often severe, tends to worsen after eating, and may improve slightly when leaning forward.
Aorta
The abdominal aorta, your body’s largest artery, runs down directly in front of the spine through the abdomen. It’s not technically “in” the back, but it’s pressed right against it. When the wall of this artery weakens and bulges outward (an abdominal aortic aneurysm), it often produces a steady, deep pain in the lower back or belly. Most people with this condition have no symptoms until the aneurysm becomes dangerously large. A rupture causes sudden, severe pain in the abdomen and lower back and is a life-threatening emergency.
Liver
The liver sits in the upper right side of the abdomen, and its back surface presses directly against the diaphragm. A portion of this posterior surface, called the bare area, has no protective lining and is in direct contact with the diaphragm and the body wall. Liver swelling, abscesses, or tumors can produce a dull ache in the right upper back or shoulder area.
Organs That Cause Back Pain by Referral
Some organs aren’t located in the back at all but can still send pain there. The gallbladder, a small organ tucked beneath the liver, is the most common example. Gallstones or gallbladder inflammation often cause sharp pain in the upper right abdomen that radiates to the right shoulder blade and mid-back. This referred pain happens because the gallbladder shares nerve pathways with structures in the upper back.
The heart can also refer pain to the upper back, particularly the left side and between the shoulder blades. In some heart attacks, especially in women, back pain may be the primary symptom rather than classic chest pain.
Organ Pain vs. Muscle Pain
Most back pain comes from muscles, ligaments, or spinal structures, not organs. But the distinction matters because organ-related pain requires different treatment. Muscular back pain typically feels like a dull ache, stiffness, or soreness that worsens with certain movements and improves when you find a comfortable position. It may cause sharp pain that radiates to the legs if nerves are involved, and it’s often accompanied by muscle spasms, weakness, or tingling.
Organ-related back pain behaves differently. It tends to stay constant regardless of how you move, doesn’t respond to stretching or position changes, and often comes with symptoms that have nothing to do with your back: fever, changes in urination, nausea, vomiting, or unexplained weight loss. Pain that wakes you from sleep, pain accompanied by fever, or pain alongside bloody urine or gastrointestinal symptoms all suggest something beyond a simple muscle problem. Sudden, tearing pain in the upper or mid-back can indicate an aortic emergency, and new back pain paired with unexplained weight loss warrants prompt evaluation.