Pain on both sides of your torso usually comes from one of a few sources: muscle strain, trapped gas in the colon, kidney problems, or inflammation in the tissue surrounding your lungs. The location, timing, and quality of the pain can help you narrow down what’s going on. Side pain that stays constant regardless of how you move points toward an internal organ, while pain that shifts when you change position or take a deep breath suggests muscles or the lining around your lungs.
Trapped Gas in the Colon
This is one of the most common and least concerning causes of pain on both sides. Your large intestine makes two sharp bends near your ribs, one on the right side (near the liver) and one on the left (near the spleen). Gas that gets stuck at the right bend can feel like a deep ache under your right ribs, sometimes mimicking gallbladder pain. Gas trapped at the left bend can radiate upward into the chest and even feel like heart-related pain. When gas accumulates at both bends, you feel it on both sides simultaneously.
This type of pain tends to come and go, often worsening after meals or when you’ve eaten foods that produce more gas. It may feel like pressure, sharp cramping, or a bloated fullness in your sides. Moving around, passing gas, or having a bowel movement typically brings relief. If this is a recurring pattern, it may point to an underlying issue like irritable bowel syndrome or food intolerances worth exploring.
Muscle Strain on Both Sides
Your oblique muscles run along both sides of your torso from your ribs to your hips. They’re active in almost every movement that involves twisting, bending, or bracing your core. A hard workout, heavy lifting, prolonged coughing, or even a vigorous sneeze can strain these muscles on both sides. The hallmark of an oblique strain is acute pain and tenderness along the lateral trunk near the rib cage, and it typically gets worse with twisting, bending sideways, coughing, or sneezing.
Bilateral muscle strain is less common than a one-sided injury because most activities load one side more than the other. But exercises that work both sides equally (think situps, rowing, or carrying heavy loads in front of your body) can cause soreness or strain on both flanks. The key distinguishing feature is that this pain changes with movement. Shifting into a more comfortable position helps. Pressing on the sore area reproduces the pain. And it tends to improve gradually over days with rest.
Kidney-Related Causes
Kidney pain is felt in the flank, the area on either side of your spine just below the ribs and above the hips. Unlike muscle pain, kidney pain doesn’t change when you shift position. It tends to stay constant and doesn’t improve without treatment.
Kidney Infections
A kidney infection usually starts as a bladder infection that travels upward, and it can affect one or both kidneys. Symptoms include fever, chills, nausea, a burning sensation when urinating, frequent urination, and urine that looks cloudy or smells unusual. You may also notice blood or pus in your urine. When both kidneys are infected, you’ll feel pain in both flanks. This is a condition that needs prompt treatment, as the infection can spread to the bloodstream.
Kidney Stones
About 12% of people who form kidney stones have them in both kidneys at the same time. The pain from kidney stones is famously intense, often described as waves of sharp, cramping pain that radiates from the back and side down toward the groin or inner thigh. If stones are present in both kidneys simultaneously, you could feel this pain on both sides, though it’s more common to feel one side flaring at a time.
Polycystic Kidney Disease
This is a genetic condition where fluid-filled cysts grow in both kidneys over time. Many people don’t know they have it until it’s found incidentally on an imaging scan or during a workup for high blood pressure. A family history is the strongest clue. As the cysts enlarge, they can cause a dull, aching pressure on both sides that gradually worsens over months or years rather than appearing suddenly.
Pleurisy and Breathing-Related Pain
Your lungs are wrapped in a thin, double-layered membrane called the pleura. Normally, a small amount of fluid between the layers lets them glide smoothly as you breathe. When these layers become inflamed, a condition called pleurisy, they rub against each other with every breath. The result is a sharp or stabbing pain in your chest or sides that gets noticeably worse when you inhale deeply, cough, or sneeze. You may also find yourself breathing in quick, shallow breaths to avoid triggering it.
Pleurisy can affect one or both sides of the chest and is often caused by a viral infection, pneumonia, or an autoimmune condition. If both sides are inflamed, you’ll feel the sharp, breath-dependent pain bilaterally. The key distinction from muscle strain is that pleurisy pain is tightly linked to your breathing cycle rather than body movement.
How to Tell Organ Pain From Muscle Pain
A few simple checks can help you figure out what you’re dealing with:
- Movement test: Muscle pain changes when you shift position, twist, or bend. It may ease when you find a comfortable posture. Organ pain, particularly from the kidneys, stays constant no matter how you move.
- Touch test: Pressing on the sore area reproduces muscle pain. Kidney pain sits deeper and isn’t as responsive to surface pressure.
- Associated symptoms: Fever, painful urination, blood in urine, nausea, or cloudy urine all point toward a kidney problem. Pain that worsens only with breathing suggests pleurisy. Pain tied to meals and bloating suggests gas.
- Timeline: Muscle pain often has a clear trigger (a workout, a fall, heavy lifting) and improves over days. Kidney pain and pleurisy tend to persist or worsen without treatment.
When Both Sides Hurting Is Serious
Most bilateral side pain turns out to be muscle soreness or gas, but certain combinations of symptoms signal something more urgent. Fever paired with flank pain raises concern for a kidney infection that could enter the bloodstream. Blood in your urine alongside side pain warrants prompt evaluation, as it can indicate stones, infection, or less commonly, something affecting the kidney tissue itself. Unexplained weight loss combined with persistent side pain, particularly in adults over 50, is a red flag that calls for imaging.
If the pain is severe and constant, came on suddenly, and doesn’t respond to over-the-counter pain relief, that pattern alone justifies getting checked. An ultrasound is typically the first imaging tool used because it’s quick and involves no radiation. If the picture isn’t clear, a CT scan provides more detailed information and can accurately identify stones, infections, abscesses, and other structural problems in and around the kidneys.