Pain on the left side of your abdomen can come from a wide range of causes, from trapped gas to conditions that need prompt medical attention. The left side of your abdomen houses parts of your stomach, pancreas, spleen, left kidney, and portions of your colon, along with the left ureter. In women, the left ovary and fallopian tube sit in the lower left area. Figuring out what’s behind the pain starts with where exactly you feel it and what other symptoms come with it.
Left Upper Abdomen Pain
Enlarged Spleen
Your spleen sits tucked under your ribcage on the left side. When it becomes enlarged, it can cause pain or a feeling of fullness in the left upper belly that sometimes spreads to the left shoulder. You might feel full after eating very little because the swollen spleen presses against your stomach. Many people with an enlarged spleen have no symptoms at all until it gets large enough to cause pressure.
A number of conditions can cause the spleen to swell, including viral infections like mononucleosis, liver disease, certain blood disorders, and autoimmune conditions. An enlarged spleen is also more vulnerable to rupturing, which can cause life-threatening internal bleeding. Pain in this area that gets worse when you take a deep breath warrants prompt medical evaluation.
Stomach and Pancreas Issues
Gastritis, stomach ulcers, and inflammation of the pancreas can all produce pain in the upper left abdomen. Gastritis often feels like a burning or gnawing sensation, while pancreatic pain tends to be deeper and can radiate to the back. These conditions are typically accompanied by nausea, vomiting, or a worsening of pain after eating.
Left Lower Abdomen Pain
Diverticulitis
Diverticulitis is one of the most common causes of left lower abdominal pain, especially in adults over 40. It happens when small pouches that form in the wall of the colon become inflamed or infected. The pain is usually acute and constant, centered in the left lower quadrant. Tenderness isolated to this area significantly increases the likelihood of diverticulitis, with one clinical analysis showing it makes the diagnosis roughly ten times more probable.
Other symptoms include nausea, constipation or diarrhea, loss of appetite, and painful urination. A low-grade fever (usually below 102°F) is common, though some people remain fever-free. A CT scan is the standard test for confirming the diagnosis and checking for complications like abscesses or perforation.
Irritable Bowel Syndrome
IBS frequently causes pain in the lower abdomen, and many people with the condition report it specifically on the lower left side. The pain is often crampy and tied to bowel habits. It tends to improve after a bowel movement and worsen during periods of stress or after eating certain trigger foods. Unlike diverticulitis, IBS pain comes and goes over weeks or months rather than arriving suddenly and staying constant.
Ovarian Cysts and Reproductive Causes
In women, a cyst on the left ovary can produce a dull ache or sharp pain below the bellybutton toward the left side. Many ovarian cysts cause no symptoms and resolve on their own, but they can occasionally twist or rupture. A ruptured cyst causes sudden, severe pelvic pain and sometimes comes with fever, vomiting, or signs of shock like cold skin, rapid breathing, and lightheadedness.
An ectopic pregnancy, where a fertilized egg implants in the left fallopian tube instead of the uterus, is another cause of left lower pain in women of reproductive age. This is a medical emergency. If you could be pregnant and develop sharp, one-sided pelvic pain, especially with vaginal bleeding or dizziness, seek immediate care.
Pain That Can Occur Anywhere on the Left Side
Kidney Stones
A stone in the left kidney or left ureter can cause pain that starts in your lower back or side and radiates toward your groin. The pain is often described as coming in waves, sometimes dull and sometimes sharp and severe. Bloody urine, painful urination, cloudy or foul-smelling urine, and a frequent urge to urinate are classic accompanying symptoms. Kidney stone pain rarely stays in one spot. It tends to shift as the stone moves through the urinary tract.
Hernias
A hernia occurs when an organ or tissue pushes through a weak spot in the surrounding muscle wall. Inguinal hernias, the most common type (accounting for about 75% of all hernias), happen in the groin area and mostly affect men. You might notice a visible bulge that appears when you strain, lift, cough, or laugh and disappears when you lie down. The sensation can range from a dull ache to a sharp pinch, or you might feel only pressure.
Hernias are often caused by years of repetitive strain rather than a single injury. A hernia that becomes trapped and can no longer be pushed back in is a surgical emergency, as the tissue can lose its blood supply.
Shingles
Shingles can cause burning or tingling pain along a strip of skin on one side of the body, including the abdomen, days before any visible rash appears. This makes it easy to mistake for an internal problem. The pain follows a nerve path, so it usually wraps around one side in a band-like pattern. Once the characteristic blistering rash shows up, the diagnosis becomes clearer.
Muscle Strain
Abdominal wall muscle strains are easy to overlook as a cause of left-sided pain. A sudden twisting motion, heavy lifting, or intense core exercise can tear muscle fibers or tendons. The pain typically worsens with movement, coughing, or pressing on the area. Athletes sometimes develop tears in the lower abdominal tendons (sometimes called a “sports hernia,” though it’s not a true hernia) from repetitive twisting.
Red Flags That Need Immediate Attention
Most left-sided abdominal pain resolves on its own or has a manageable cause. But certain symptoms signal something more serious. Seek emergency care if you experience:
- Sudden, severe pain that comes on quickly and doesn’t let up
- A rigid or distended abdomen that feels hard to the touch
- Signs of shock such as cold or clammy skin, rapid breathing, lightheadedness, or weakness
- Bloody vomit or stool, or dark, tarry stools
- High fever (above 101°F) with abdominal pain
- Fainting or near-fainting
- Pain with a positive pregnancy test
Abdominal pain that persists for more than a few days, keeps returning, or gradually worsens also deserves evaluation, even without the dramatic red flags above. A physical exam combined with blood work and imaging (usually ultrasound or CT, depending on what’s suspected) can narrow down the cause quickly in most cases.