Back pain usually originates from musculoskeletal issues like muscle strain or disc problems. However, discomfort can also be referred pain, meaning it stems from a problem elsewhere in the body. Referred pain happens when an internal organ shares nerve pathways with a distant area, causing the brain to misinterpret the signal’s origin. Understanding these non-muscular sources is important, as organ-related pain often requires more urgent attention than typical back strain.
Kidney and Urinary Tract Pain
The kidneys are situated high in the abdomen, just beneath the rib cage on either side of the spine, making them a frequent source of back discomfort. Pain from the kidneys or upper urinary tract is typically felt in the flank area, between the lower ribs and the hips. This discomfort is often unilateral, affecting only one side of the back, and may radiate downward toward the groin or abdomen.
Kidney stones cause intensely sharp pain known as renal colic, often described as coming in waves as the stone moves through the ureter. This pain is unrelenting and does not improve with changes in position, unlike muscle-related back pain. A kidney infection (pyelonephritis) usually presents as a dull, constant ache in the flank, often accompanied by systemic symptoms.
Infections are frequently signaled by a high fever and chills. Urinary symptoms pointing toward a kidney cause include a frequent or urgent need to urinate, a burning sensation, or the presence of blood or a foul odor in the urine. The simultaneous presence of fever and flank pain indicates that a urinary tract infection may have progressed to the kidney and requires medical evaluation.
Referred Pain from Digestive Organs
Problems within the upper digestive organs can generate back pain due to shared neural pathways connecting the gut to the spinal cord. The pancreas, located behind the stomach and close to the spine, is a common source. Inflammation of the pancreas (pancreatitis) typically causes a deep, boring pain that originates in the upper abdomen and radiates straight through to the mid-back.
This pain often intensifies after eating, especially fatty foods, as the pancreas is stimulated to release digestive enzymes. A distinct feature is its positional nature; the discomfort feels worse when lying flat and may be partially relieved by leaning forward. The severity of back pain in acute pancreatitis can be significant, sometimes overshadowing abdominal symptoms.
The gallbladder and liver, located in the upper right quadrant, can also refer pain to the back. Gallstones or inflammation (cholecystitis) cause pain that radiates to the upper right back or below the right shoulder blade (scapular region). This referral pattern occurs due to the nerve connection between the gallbladder and the diaphragm. The pain is typically sharp or cramping and is often triggered by consuming a high-fat meal.
Vascular and Pelvic Organ Concerns
A sudden onset of back pain can signal a severe vascular event, such as an abdominal aortic aneurysm (AAA). The aorta is the body’s largest artery, and an aneurysm is a dangerous bulge in its wall near the spine. When an AAA expands rapidly or ruptures, it causes severe, constant pain felt deep in the lower back or abdomen.
This emergency pain may be described as tearing or ripping. An expanding aneurysm can also cause a throbbing or pulsing sensation in the abdomen. Since a ruptured AAA is a life-threatening emergency, sudden, severe back pain accompanied by a pulsating feeling demands immediate medical attention.
Other sources of referred back pain are found in the pelvic region, affecting the lower back and sacral area. Conditions involving the female reproductive system, such as endometriosis or ovarian cysts, can cause lower back pain, especially around the menstrual cycle. Similarly, inflammation of the prostate gland (prostatitis) can cause a chronic, dull ache in the lower back in men.
Red Flag Symptoms Requiring Immediate Attention
While most back pain is benign, certain accompanying symptoms, known as red flags, suggest the discomfort originates from an internal organ or a serious spinal condition. Any back pain that is sudden, severe, unrelenting, or not relieved by rest or positional changes should be evaluated promptly. This is especially true if the pain is accompanied by a pulsing or throbbing sensation in the abdomen, indicating a vascular emergency.
The presence of the following symptoms alongside back pain requires immediate medical attention:
- High fever, chills, or unexplained weight loss, which may signal a serious infection or systemic disease.
- New numbness or weakness in the legs (changes in neurological function).
- Sudden loss of bowel or bladder control (a serious red flag).
- Persistent nausea, vomiting, or jaundice (yellowing of the skin), suggesting a problem with digestive organs like the pancreas or liver.