An infection can cause both back pain and abdominal pain simultaneously. This combination of symptoms often suggests that an internal organ is inflamed or infected, as opposed to a simple muscle strain. The connection between pain in the abdomen and the back is frequently tied to the body’s nervous system structure. This dual pain pattern should always be taken seriously, as it can be a sign of an infection requiring immediate medical attention.
Understanding the Pain Connection
Pain originating from internal organs, known as visceral pain, is typically diffuse and difficult to pinpoint precisely. Because the nerve supply to the viscera is less dense than the skin, the exact location of the problem is often poorly perceived, causing pain to be felt elsewhere, such as the back.
The physiological mechanism involves a convergence of nerve pathways within the spinal cord. Nerves transmitting signals from an internal organ and nerves relaying sensation from the back often meet on the same secondary nerve cells. The brain misinterprets this signal, projecting the pain sensation to the more densely innervated somatic area, usually the skin or muscle of the back. Inflammation from an infection can also sensitize these shared nerve pathways, making the pain more intense and widespread.
Key Infections That Cause Dual Pain
Several types of infections can irritate internal organs and trigger pain felt in both the abdomen and the back.
Kidney Infection (Pyelonephritis)
A common example is a urinary tract infection (UTI) that progresses to pyelonephritis, a kidney infection. Pyelonephritis causes inflammation of the kidney tissue, which is located deep in the abdomen near the back muscles and ribs.
The resulting pain is often felt as flank pain, which is tenderness or aching in the side and upper back, sometimes radiating towards the lower abdomen and groin. This is accompanied by lower abdominal symptoms like a frequent and urgent need to urinate, or a burning sensation during urination.
Diverticulitis
Gastrointestinal infections can also cause this dual pain, particularly severe diverticulitis. Diverticulitis involves the infection and inflammation of small pouches, called diverticula, that form in the lining of the colon. Since the sigmoid colon is situated close to the lower back, the inflammation can irritate nearby nerves.
This irritation leads to lower abdominal pain, typically in the left lower quadrant, which can radiate through tissue planes to cause lower back pain. The back pain can manifest as a constant, dull ache.
Pelvic Inflammatory Disease (PID)
In women, Pelvic Inflammatory Disease (PID) is another infection causing both lower abdominal and back pain. PID is an infection of the upper female reproductive organs, including the uterus, fallopian tubes, and ovaries, often caused by sexually transmitted bacteria. The infection causes inflammation in the pelvic cavity, resulting in tenderness and a dull ache in the lower abdomen or pelvis. This inflammation can also irritate the surrounding nerves, leading to lower back pain.
Recognizing Serious Symptoms and When to Seek Care
The presence of combined abdominal and back pain, especially when infectious, is often accompanied by systemic symptoms. A high fever and shaking chills are significant indicators that the body is fighting a spreading bacterial infection. These systemic signs differentiate an infection from a non-infectious cause like a muscle strain.
Accompanying symptoms include persistent nausea, vomiting, or diarrhea. For kidney infections, look for changes in urination, including blood in the urine, cloudy or foul-smelling urine, or pain during urination. Pain that is sudden in onset, severe, or does not lessen when changing positions should prompt immediate attention.
Emergency medical care is required if dual pain is paired with signs of a severe, life-threatening infection, such as sepsis. These signs include:
- Confusion or sudden mental status change.
- A rapid heart rate.
- Very low blood pressure.
- Extreme fatigue.
A rapidly worsening condition, or pain that is so intense it prevents movement, indicates a medical emergency.