A peptic ulcer is an open sore that develops on the inner lining of the stomach (a gastric ulcer) or in the upper part of the small intestine (a duodenal ulcer). These sores form when the protective mucous lining is eroded by stomach acid and digestive juices. While the most common symptom is a burning or gnawing pain in the upper abdomen, stomach ulcers can cause back pain. This occurs through referred pain, where discomfort from the internal organ is perceived in a different part of the body.
How Ulcers Cause Referred Back Pain
The connection between an abdominal organ and the back lies in the shared pathways of the nervous system. Pain originating from internal organs (viscera) is carried by visceral nerves that are not specialized for precise location. These nerves enter the spinal cord at the same levels as the somatic nerves that transmit signals from the skin and muscles of the back. The stomach and duodenum connect to spinal cord segments between T5 and T10. Because the central nervous system receives input from both the internal organs and the back muscles at these levels, the brain struggles to accurately pinpoint the source of the pain. The brain interprets the visceral irritation from the ulcer as originating from the more familiar location of the back, creating referred back pain often localized to the middle or upper-middle back.
Characteristics of Ulcer-Related Back Pain
Back pain resulting from an uncomplicated ulcer typically presents with distinct qualities and timing patterns related to digestion. The sensation is often described as a deep, gnawing, burning, or aching discomfort in the mid-back area. The location can sometimes offer a clue: duodenal ulcers more often refer pain slightly to the right, and gastric ulcers potentially refer pain slightly to the left. The timing of the pain in relation to eating is a hallmark characteristic. Duodenal ulcer pain often improves immediately after food consumption, as the food buffers the acid, but then recurs intensely about one to three hours later as the stomach empties. Gastric ulcer pain, conversely, may be aggravated shortly after eating when the stomach produces more acid. The pain may frequently wake a person up during the night due to the cyclic nature of acid secretion.
Serious Ulcer Complications and Back Pain
While standard referred back pain from an ulcer is manageable, the sudden onset of severe, unrelenting back pain can signal a life-threatening complication. This change in pain pattern requires immediate medical attention, as it indicates the ulcer is no longer confined to the lining of the digestive tract.
Penetration
Penetration occurs when the ulcer erodes entirely through the stomach or duodenal wall and into an adjacent organ, most commonly the pancreas. When the ulcer penetrates the pancreas, it can cause acute pancreatitis, leading to severe, persistent, and deep pain that radiates directly to the back. This type of back pain is not relieved by antacids and is often accompanied by nausea and vomiting, indicating a profound internal inflammatory response.
Perforation
Perforation occurs when the ulcer creates a complete hole, allowing the contents of the stomach or duodenum to spill into the sterile abdominal cavity. This event typically results in the sudden, agonizing onset of sharp, generalized abdominal pain that rapidly intensifies and can radiate to the back or shoulder. The spilled digestive contents cause widespread irritation and inflammation of the abdominal lining, known as peritonitis, which is a surgical emergency.
Other Common Causes of Back Pain
Back pain is an extremely common complaint, and the majority of cases are not related to an underlying ulcer. The most frequent cause is musculoskeletal strain, involving the muscles, ligaments, or discs of the spine. This type of pain is often linked to movement, injury, or poor posture. Other internal organ issues can also cause referred back pain that might be confused with an ulcer. Kidney stones or a kidney infection, for example, often cause pain in the flank that wraps around to the back. Spinal conditions such as degenerative disc disease or a herniated disc are responsible for many cases of chronic back pain. A careful assessment of the pain’s quality, location, and relationship to eating is necessary to distinguish an ulcer-related issue from these common causes.