Back pain and stomach discomfort can be related, and the pain felt in one area can be caused by a problem originating in the other. This connection results from the intricate way the human nervous system is structured, where nerves supplying internal organs share pathways with those supplying the back and abdomen. Understanding this biological overlap is the first step toward accurately identifying the source of the discomfort.
Understanding Referred Pain
Referred pain is the phenomenon where pain is felt in a location different from its source. This occurs because sensory nerve fibers from internal organs (viscera) converge with nerve fibers from the skin and musculoskeletal system (soma) onto the same neurons in the spinal cord. This process is called viscero-somatic convergence.
Because internal organs are less densely supplied with sensory nerve endings, the brain misinterprets the signal’s origin. It perceives the pain as coming from the more familiar somatic area, such as the back or abdomen. This “shared wiring” explains why a serious issue with an organ can present as seemingly common back pain.
Musculoskeletal Causes of Radiating Pain
In some cases, the back structure itself is the origin of the pain, which then radiates forward to the stomach area through nerve irritation. A herniated disc, for example, can press on spinal nerves as they exit the vertebral column. Since these nerves supply sensation to both the back and parts of the abdomen, the pain may be felt in the stomach area, sometimes described as sharp or cramping.
Muscle strain, particularly involving the psoas muscle, is another common musculoskeletal cause. The psoas muscle runs from the lower spine to the femur and plays a significant role in hip flexion. When this muscle becomes strained or inflamed, it causes pain in the lower back, which is often referred to the groin or abdomen.
Internal Organ Conditions Mimicking Back Pain
Visceral pain referral often indicates a problem with an internal organ mistakenly felt in the back. Pancreatitis, or inflammation of the pancreas, frequently causes pain that originates in the upper belly and radiates straight through to the back. The pain is typically constant, severe, and dull, and it may worsen after eating fatty meals.
Kidney issues are another common source of referred pain, as the kidneys are located near the back muscles. A kidney stone moving into the ureter can cause renal colic, an excruciating, intermittent pain that begins in the flank and travels forward to the lower abdomen or groin. This sharp, cramping pain may be accompanied by nausea and vomiting.
A less common but more serious cause of combined back and abdominal pain is an abdominal aortic aneurysm (AAA), a bulging in the wall of the aorta. A growing AAA can cause deep, constant pain in the lower back or a throbbing sensation near the belly button. If the aneurysm ruptures, it causes sudden, severe, and tearing pain in the abdomen and lower back, representing a life-threatening medical emergency.
When to Seek Medical Attention
The combination of back pain and stomach pain can sometimes signal a medical issue that requires immediate attention. Certain accompanying symptoms are considered “red flags” that should prompt an urgent visit to an emergency room.
Urgent Warning Signs
Seek immediate care if the pain is accompanied by any of the following:
- Sudden, intense, or ripping pain in the back or abdomen, which could suggest a ruptured aneurysm or other acute internal event.
- High fever, chills, or unexplained weight loss, which may indicate an infection or a tumor.
- New loss of bowel or bladder control.
- Sudden numbness and weakness in the legs or groin area, indicating severe nerve compression.
If the pain is persistent and not relieved by rest or simple measures, a medical consultation is necessary to determine the underlying cause.