Pain in the left lower back can arise from various structures, including internal organs. This information provides general insights into organs located in the left lower back and is not a substitute for professional medical advice.
The Left Kidney and Adrenal Gland
The left kidney is a bean-shaped organ located towards the back of the abdominal cavity, just below the rib cage. It filters waste products, excess water, and toxins from the blood to produce urine, maintaining the body’s fluid and electrolyte balance.
Perched atop the left kidney is the left adrenal gland. These glands are part of the endocrine system and produce hormones that regulate metabolism, blood pressure, and stress response.
Problems with the left kidney often manifest as pain in the left lower back or flank region. Kidney stones, hard deposits of minerals and salts, can cause sharp, cramping pain that radiates from the back and side to the lower abdomen or groin as they move through the urinary tract. A kidney infection (pyelonephritis) can also lead to sudden and severe pain in the lower back or side, often accompanied by fever, chills, and painful urination. The inflammation and swelling of the kidney during an infection can put pressure on nearby muscles and nerves, contributing to the perceived back pain.
Segments of the Large Intestine
The large intestine has segments positioned in the left lower abdominal and back region, specifically the descending and sigmoid colon. The descending colon extends downwards on the left side of the abdomen, storing food remains. The sigmoid colon, an S-shaped section, connects to the rectum and holds fecal matter. These segments absorb water and electrolytes and form stool.
Conditions affecting these parts of the large intestine can lead to discomfort or pain perceived in the left lower back. Constipation can cause dull pain in the lower back as accumulated stool in the colon or rectum presses on nerves and muscles. Fecal impaction, a severe form of constipation, can also result in back pain. Irritable Bowel Syndrome (IBS), a chronic gastrointestinal disorder, causes lower back pain, often due to gas pressure, colon spasms, or swollen bowels.
Diverticulitis, a condition where small pouches in the colon (diverticula) become inflamed or infected, causes pain in the lower left abdomen that can radiate to the lower back. This referred pain occurs because the inflamed colon shares nerve pathways with the lower back. The pain can range from mild cramps to severe, persistent discomfort.
Female Reproductive Organs
For individuals with female anatomy, certain reproductive organs can contribute to pain experienced in the left lower back. The left ovary and fallopian tube are situated in the lower pelvic area. Pain originating from these structures can often be felt as referred pain in the left lower back due to shared nerve pathways.
Ovarian cysts, fluid-filled sacs on or in the ovaries, can cause a dull, aching lower back pain, especially if they grow large enough to press on surrounding organs and tissues. Larger cysts or those that rupture can lead to sudden and severe pain.
Endometriosis, a condition where tissue similar to the uterine lining grows outside the uterus, can cause chronic lower back pain. This pain may intensify during menstrual periods and can be due to inflammation or compressed nerves.
Pelvic Inflammatory Disease (PID), an infection of the female reproductive organs including the uterus, fallopian tubes, and ovaries, can also result in lower back pain. PID often presents with persistent lower abdominal or pelvic pain that can extend to the lower back. These conditions highlight how issues within the female reproductive system can manifest as discomfort in the left lower back region.