Causes of Lower Left Side Abdominal and Back Pain

There are a wide range of causes of lower back pain on the left side.
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Experiencing pain in your lower abdomen AND your lower back can be overwhelming and frightening. Pain in the lower left abdomen and back can signal a problem with any of a number of organs in the abdomen or pelvis.

The pain could be caused by something as simple as constipation or as serious as a kidney stone. But being aware of the danger signs and symptoms of more serious conditions is important to help you determine when to see a doctor. Here's a list of possible conditions as well as when to seek medical attention.


Diverticulitis is a common cause of pain in the lower left abdomen and back, and an increasingly frequent reason for hospital stays. So what is it? As you age, small pouches can develop along the walls of the colon. Most commonly, these pouches develop in the sigmoid colon located on the left side of the abdomen.

Diverticulitis occurs when these pouches become inflamed, resulting in pain in the left lower abdomen that might also be felt in the back. Other possible symptoms of diverticulitis include fever, nausea, vomiting and constipation or diarrhea.

Often times, constipation can cause left-sided abdominal and back pain.
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Other Digestive System Causes

Colon problems other than diverticulitis can also cause pain in the lower left abdomen and back. Something as simple as constipation can cause pain as your colon distends with stool. If painful constipation is associated with bloating and an inability to pass gas, a colon blockage may be present.

A tumor involving the last portion of the colon can also cause left-sided abdominal and back pain. Colon cancer is the second leading cause of cancer-related deaths in the United States, reports the Centers for Disease Control and Prevention. Symptoms can include changed stool consistency, bloating and/or bloody stools.

Read more: 7 Signs Your Gut Is Out of Whack

Urinary System Causes

Severe left-sided back pain that radiates into the lower abdomen could indicate a kidney stone or a kidney infection. Kidney stones develop from excess crystal-forming substances in the urine. When larger stones move through the urinary system, they might cause a blockage, leading to pain, bloody urine and nausea.

Similar pain can also be felt with a urinary tract infection involving the kidney, a condition called pyelonephritis. Typical symptoms include one-sided abdominal and back pain, burning with urination, increased urinary frequency, nausea, vomiting, fever and chills.

Reproductive System Causes

Left-sided abdominal and back pain in women could indicate a problem with the ovary or fallopian tube on that side. An infection, cyst or twisting of the ovary can cause severe pain that generally worsens over time.

A pregnancy located in the left fallopian tube or ovary instead of the uterus — a condition known as an ectopic pregnancy — is another possible cause for pain and may be accompanied by vaginal bleeding.

In men, a testicular infection, tumor or twisting of the left testicle commonly causes pain that radiates from the testicle into the left side of the abdomen and back.

Read more: The 10 Most Annoying Women's Health Issues and How to Fix Them

When to See Your Doctor

Call your doctor right away if you develop pain in the lower left abdomen and back, especially if it doesn't go away in a few days, or is severe or worsening. Seek immediate medical attention if you experience abdominal and back pain accompanied by any of the following symptoms:

  • Fever
  • Bloody stool
  • Persistent vomiting
  • Inability to pass gas
  • Vaginal bleeding
  • Dizziness, lightheadedness or fainting

Reviewed and revised by: Tina M. St. John, M.D.

Is This an Emergency?

If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911. If you think you may have COVID-19, use the CDC’s Coronavirus Self-Checker before leaving the house.