True hip pain originates from the joint itself, presenting as a deep ache localized in the groin or the front of the hip. Pain felt on the side or in the buttock is less often a sign of a problem within the joint. Due to the complex network of nerves and the proximity of structures in the pelvis and lower torso, discomfort from other areas frequently presents as hip pain (referred pain). Accurately pinpointing the origin is necessary because a treatment designed for a joint issue will not resolve a problem originating elsewhere.
Referred Pain from the Lower Back
Problems originating in the lumbar spine frequently mimic discomfort in the hip and buttocks. Lumbar radiculopathy occurs when a spinal nerve root is irritated or compressed, often due to a herniated disc or spinal stenosis. Since the L4, L5, and S1 nerve segments supply the hip and leg, the resulting sensation can be falsely perceived as a hip problem.
This nerve-related pain is often described as sharp, shooting, or electric, traveling down the back of the thigh and potentially below the knee—a pattern uncommon in isolated hip joint arthritis. Unlike true hip pain, which worsens with weight-bearing activities, radicular pain is positional. Pain may intensify with prolonged sitting, standing, or specific movements that compress the nerve root, such as bending backward.
Facet joint arthritis, which is degeneration in the small joints along the back of the spine, can also refer pain to the buttock and hip area. This discomfort is often described as a deep, dull ache, and it may be accompanied by tingling, numbness, or muscle weakness in the leg, which are signs of nerve involvement. Pain from the lumbar spine is often aggravated by spinal movements, whereas hip pain is typically aggravated by hip rotation.
Pelvic and Sacroiliac Joint Sources
The sacroiliac (SI) joint and the deep muscles of the buttock are a common source of pain mistaken for a posterior hip problem. The SI joint connects the sacrum to the pelvis. Dysfunction in this joint, caused by inflammation or misalignment, can produce a dull ache localized to the buttock crease and the lower back.
Pain from the SI joint rarely travels below the knee, distinguishing it from lumbar radiculopathy. It is often aggravated by asymmetrical loading activities, such as standing on one leg or climbing stairs, and can be felt when rolling over in bed. The limited movement of the SI joint means the pain is more stable in its location compared to the shifting discomfort of a nerve issue.
Piriformis syndrome is a deep gluteal condition that mimics hip pain, occurring when the piriformis muscle, situated deep in the buttock, irritates the sciatic nerve. When this muscle spasms or becomes tight, it compresses the sciatic nerve, causing buttock pain that radiates down the back of the leg. This syndrome is a non-spinal cause of sciatica-like symptoms, often producing pain worse after prolonged sitting or when the hip is rotated against resistance.
Groin and Abdominal Wall Conditions
Anterior hip pain, felt deep in the groin, is the location for true intra-articular hip pathology, but several non-orthopedic conditions can mimic this presentation. Inguinal and femoral hernias are a cause of groin pain often misdiagnosed as a hip flexor strain or joint issue. These hernias occur when internal tissue pushes through a weak spot in the abdominal wall, causing a visible bulge or pressure in the groin.
The discomfort from a hernia is often described as a sharp pain that worsens with activities that increase intra-abdominal pressure, like coughing, sneezing, or heavy lifting. Femoral hernias, which are more common in women due to a broader pelvis, can present as a small, painful lump just below the groin crease.
Conditions of the internal organs can also cause referred pain, as they share nerve pathways with the hip and groin area.
Urologic Conditions
Urologic issues, such as kidney stones, can cause severe pain that radiates from the flank and abdomen directly into the groin area as the stone travels down the ureter. This pain is episodic and accompanied by other symptoms like nausea or blood in the urine, which helps distinguish it from a musculoskeletal hip issue.
Gynecologic Conditions
Gynecologic conditions like endometriosis, where tissue similar to the uterine lining grows outside the uterus, can cause cyclical hip and groin pain. Endometriotic implants near pelvic nerves, such as the obturator or sciatic nerve, can cause inflammation and pressure that is felt as deep, persistent hip discomfort, often worsening during the menstrual cycle.
How Pain Location and Movement Aid Diagnosis
The precise location of pain and its response to specific movements are the most useful tools for distinguishing true hip joint problems from mimics. Pain originating from within the hip joint is almost always felt in the front of the hip or groin, and it is reproduced by rotating the leg. The FADIR test (Flexion, Adduction, Internal Rotation) is effective at compressing the joint space and provoking pain in cases of intra-articular pathology like a labral tear or arthritis.
Conversely, conditions originating outside the joint respond differently to movement. Pain from the sacroiliac joint is often elicited by the FABER test (Flexion, Abduction, External Rotation), where pressure is applied to the knee while the hip is in a figure-four position, stressing the SI joint ligaments. For spinal issues, the straight leg raise test can reproduce radiating pain down the leg, suggesting nerve root irritation, which is not a finding in isolated hip joint disease.
Observing a patient’s gait and ability to bear weight also provides clues. True hip joint arthritis often causes a limp and a noticeable limitation in the hip’s internal rotation, while many spinal conditions or soft tissue injuries do not affect this specific range of motion. A medical professional uses this combination of location, movement response, and associated symptoms like numbness or fever to narrow down the possible source of the discomfort.