Pain where the femur meets the hip can come from dozens of different structures packed into one of the most heavily loaded joints in the body. The hip is a ball-and-socket joint where the rounded top of the femur (the femoral head) sits inside a cup-shaped socket in the pelvis, and every step you take sends forces of several times your body weight through that interface. Cartilage, a ring of fibrous tissue called the labrum, a thick joint capsule, tendons, bursae, and nerves all converge here, and trouble with any one of them can produce pain that feels like it is coming from “the hip.” What follows is a walkthrough of the most common culprits, how they overlap, and what tells them apart.
A Quick Look at the Joint Itself
The hip joint’s stability comes from its deep socket (the acetabulum), a surrounding capsule of tough connective tissue, and several strong ligaments that constrain the femoral head during movement. The capsule and ligaments together guide how load is distributed across the surfaces of the femur and acetabulum during weight-bearing activities like walking, running, and climbing stairs.1PubMed Central. Hip Joint Capsular Anatomy, Mechanics, and Surgical Management Lining both surfaces is a thin layer of articular cartilage that allows smooth, nearly frictionless motion. Around the rim of the socket sits the labrum, a fibrocartilage gasket that deepens the socket and helps seal fluid inside the joint. Understanding these basic parts matters because most hip pain traces back to damage or dysfunction in one or more of them.
Osteoarthritis and Cartilage Wear
By far the most common cause of hip pain in adults over 50 is osteoarthritis. The articular cartilage that cushions the femoral head and acetabulum gradually erodes, eventually leaving bone grinding against bone.2Springer Link. Ageing and Osteoarthritis Early on, pain tends to appear during or after activity and ease with rest. As cartilage loss advances, pain can become constant and stiffness can make simple tasks like tying shoes difficult. Risk factors include age, excess body weight, prior joint injuries, and a family history of the disease. Because osteoarthritis develops slowly, many people live with low-grade hip discomfort for years before seeking help, often attributing the ache to “getting older.” That delay can matter: by the time someone sees a doctor, cartilage loss may be significant enough that conservative treatment has limited runway.
Femoroacetabular Impingement
Femoroacetabular impingement, usually shortened to FAI, is a mechanical problem caused by abnormal bone shapes at the junction of the femur and the hip socket.3PubMed Central. Anatomical Mechanisms of Femoroacetabular Impingement and Its Role in the Progression to Hip Osteoarthritis: A Systematic Review There are two main varieties. In cam-type impingement, the femoral head is not perfectly round; an extra bump of bone on the head-neck junction jams against the rim of the socket during movement. In pincer-type impingement, the socket itself is too deep or extends too far over the femoral head, so the rim of the acetabulum clips the neck of the femur. Many people have a mix of both.
The pain from FAI typically shows up in the groin or deep in the front of the hip, and it gets worse with prolonged sitting, squatting, or any motion that pushes the hip into deep flexion and internal rotation. What makes FAI important beyond the immediate discomfort is that repeated impingement can damage the labrum and shear off articular cartilage over time, setting the stage for early osteoarthritis. Not everyone with impingement morphology on imaging actually has symptoms, though. Plenty of people walk around with cam or pincer anatomy and never feel a thing, which complicates the question of when to intervene.
Labral Tears
The labrum is that ring of fibrocartilage around the acetabular rim. It absorbs shock, helps distribute pressure evenly, lubricates the joint, and deepens the socket for stability.4PubMed Central. A comprehensive review of hip labral tears When the labrum tears, the most common complaint is pain in the front of the hip or groin. Mechanical symptoms like clicking, catching, locking, or a sensation that the hip is giving way are also frequent. Less commonly, the pain radiates into the buttock.
Labral tears have several causes. FAI is one of the biggest drivers, since the bony contact literally grinds into the labrum. Trauma from a fall, a car accident, or a sports collision can tear it acutely. Hip dysplasia, where the socket is abnormally shallow, overloads the labrum because it has to compensate for the missing bony coverage. Simple degeneration with age is another pathway. And people with naturally loose ligaments or excess joint mobility may stress the labrum beyond its capacity during normal activities. Because labral damage is also linked to the later development of osteoarthritis, catching it early can change the long-term trajectory of the joint.
Avascular Necrosis of the Femoral Head
Avascular necrosis (AVN) happens when the blood supply to the femoral head gets disrupted, causing the bone tissue to die.5PubMed Central. Avascular Necrosis of Femoral Head-Overview and Current State of the Art The femoral head is particularly vulnerable because its blood supply relies on a few small arteries that can be damaged by hip fracture, dislocation, long-term corticosteroid use, heavy alcohol consumption, or diseases that affect clotting. Local arterial disease in the vessels feeding the femoral head may also play a role.6PubMed. Avascular necrosis and the blood supply of the femoral head
AVN often starts with a vague ache in the groin or hip that worsens gradually over weeks to months. Pain can spike when you bear weight, and range of motion progressively shrinks. If the dead bone collapses, the femoral head loses its round shape, cartilage breaks down rapidly, and the joint essentially self-destructs. Early-stage AVN may respond to procedures that preserve blood flow and relieve pressure inside the bone, but once collapse occurs, hip replacement is typically the only reliable option. That makes early detection with MRI critical, since plain X-rays often look normal in the beginning.
Pain on the Outside of the Hip
Not all hip pain originates inside the joint. One of the most common sources of pain felt on the outer side of the hip, over the bony prominence you can feel when you press on the side of your thigh, is greater trochanteric pain syndrome (GTPS). For decades, this was called “trochanteric bursitis,” implying that an inflamed bursa was the problem. Imaging studies have shown that the underlying cause is more often damage to the gluteus medius or gluteus minimus tendons where they attach to the greater trochanter.7PubMed. MRI and US of gluteal tendinopathy in greater trochanteric pain syndrome The tendons undergo degeneration (tendinosis) or partial tearing rather than straightforward inflammation.8PubMed. Greater trochanteric pain syndrome and gluteus medius and minimus tendinosis: nonsurgical treatment
GTPS is especially common in middle-aged women and runners. The hallmark is tenderness right over the outside of the hip that worsens with lying on the affected side, climbing stairs, or walking for long distances. Because the pain sits laterally rather than in the groin, distinguishing GTPS from an intra-articular problem like osteoarthritis or a labral tear is usually straightforward once a clinician knows what to look for. Treatment leans heavily on targeted exercise to strengthen the gluteal muscles, load management, and sometimes corticosteroid injections for short-term relief.
Stress Fractures of the Femoral Neck
The femoral neck, the narrow bridge of bone connecting the femoral head to the shaft, can develop small cracks from repetitive loading. These stress fractures are uncommon in the general population but show up more often in long-distance runners and military recruits. Women appear to be at higher risk, particularly if eating disorders, missed menstrual periods, or low bone density are part of the picture.9PubMed Central. Management and treatment of femoral neck stress fractures in recreational runners: a report of four cases and review of the literature
The pain usually centers in the groin and gets worse during running or other impact activities, then gradually becomes persistent even during walking. Because X-rays can miss early stress fractures, MRI is the gold standard for catching them before the bone gives way completely. A femoral neck stress fracture that progresses to a full fracture is a surgical emergency, so any runner with unexplained, worsening groin pain should take it seriously rather than training through it.
Snapping Hip Syndrome
Some people hear or feel a visible “snap” around the hip during movement. Snapping hip syndrome is divided into external and internal types. External snapping comes from the iliotibial band sliding over the greater trochanter on the outside of the hip. Internal snapping is typically caused by the iliopsoas tendon catching on a bony prominence, most often the femoral head itself, as the hip moves from flexion to extension.10PubMed Central. Snapping Hip Syndrome: A Comprehensive Update A third category, intra-articular snapping, comes from loose bodies or labral tears inside the joint.11PubMed Central. Understanding and Treating the Snapping Hip
Many snapping hips are painless and need no treatment. When the snapping becomes painful, it is usually because the tendon has become irritated from repeated friction. Dancers and athletes who cycle the hip through extreme ranges of motion are the classic patients. Stretching, strengthening, and activity modification resolve most cases; surgery is reserved for the minority where conservative measures fail.
Childhood Hip Conditions That Resurface Later
Two pediatric hip disorders can reshape the proximal femur in ways that lead to impingement and pain years later. Legg-Calvé-Perthes disease, which disrupts blood flow to the femoral head during childhood, and slipped capital femoral epiphysis (SCFE), where the growth plate at the top of the femur shifts out of position in older children and adolescents, both alter the three-dimensional shape and function of the femoral head and neck.12PubMed Central. 3-dimensional metrics of proximal femoral shape deformities in Legg-Calvé-Perthes disease and slipped capital femoral epiphysis These shape changes frequently produce femoroacetabular impingement as the child grows into adulthood.13PubMed. Legg-Calvé-Perthes disease and slipped capital femoral epiphysis: major developmental causes of femoroacetabular impingement
If you had hip problems as a child, even ones that seemed to resolve, and you now develop groin pain in your 20s or 30s, the connection is worth exploring with your doctor. The altered bone geometry from these conditions speeds up cartilage damage and labral wear, so early intervention can slow the progression toward osteoarthritis.
Nerve Entrapment and Referred Pain
Several nerves pass through or near the hip and can become compressed or irritated, creating pain that mimics joint pathology. The sciatic nerve, femoral nerve, lateral femoral cutaneous nerve, and obturator nerve are all potential culprits. Piriformis syndrome, where the piriformis muscle in the buttock compresses the sciatic nerve, is one of the better-known examples. These entrapment neuropathies are often underdiagnosed because their symptoms overlap heavily with joint problems.14Radiographics. MR imaging of entrapment neuropathies of the lower extremity. Part 1. The pelvis and hip
Adding another layer of confusion, the lumbar spine can send pain directly into the hip region. People with both hip and lumbar spine pathology commonly report low back pain along with pain in the buttock, groin, thigh, and sometimes even the knee.15Journal of the American Academy of Orthopaedic Surgeons. Differentiating Hip Pathology From Lumbar Spine Pathology: Key Points of Evaluation and Management Disc herniations, spinal stenosis, and facet joint arthritis can all refer pain to the hip area. Sorting out whether the hip, the spine, or both are responsible requires a thorough examination, and getting it wrong means treating the wrong structure.
Septic Arthritis
Rarely, hip pain comes from infection inside the joint itself. Septic arthritis of the native adult hip is uncommon but dangerous, carrying an estimated mortality rate of about 11% and a high risk of lasting joint damage if not treated quickly. Staphylococcus aureus is the most frequently identified bacterium, though a surprisingly large proportion of cultures come back negative, ranging from roughly 17% to 78% across published studies.16PubMed Central. Management of septic arthritis of the hip joint in adults. A systematic review of the literature The classic presentation is sudden onset of severe hip pain with fever, inability to bear weight, and restricted motion in all directions. It requires urgent drainage and intravenous antibiotics. Anyone with a sudden, severe flare of hip pain along with fever or feeling systemically unwell should seek emergency medical attention rather than waiting.
How Doctors Figure Out the Source
With so many potential pain generators in close proximity, diagnosing hip pain reliably takes a combination of history, physical examination, and imaging. On physical exam, two commonly used maneuvers give clinicians useful information. The FADIR test (flexion, adduction, internal rotation of the hip) has been found to be highly sensitive for labral tears, meaning it rarely misses one, while the FABER test (flexion, abduction, external rotation) has been found to have the highest specificity for labral pathology when compared against MRI and surgical findings.17PubMed Central. Sensitivity and Specificity for Physical Examination Tests in Diagnosing Prearthritic Intra-Articular Hip Pathology Are Highly Variable: A Systematic Review That said, sensitivity and specificity for individual hip examination tests are highly variable across studies, so no single maneuver is definitive on its own.
For imaging, standard X-rays are usually the starting point. They can reveal joint-space narrowing in osteoarthritis, cam or pincer morphology in FAI, and bony abnormalities in AVN. When soft-tissue pathology like labral or cartilage damage is suspected, MRI is the next step. For detecting labral tears and cartilage lesions specifically, direct MR arthrography, where contrast dye is injected into the joint before the scan, tends to outperform standard MRI.18PubMed. MRI of Labral and Chondral Lesions of the Hip Injecting contrast is more involved, but it highlights small tears and cartilage defects that a regular MRI might miss.19PubMed Central. Magnetic resonance arthrography of the hip: technique and spectrum of findings in younger patients Even with arthrography, sensitivity for cartilage lesions is imperfect, so clinical judgment still plays a large role in deciding when the imaging findings match the clinical picture.20PubMed. Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography
Surgery Versus Physical Therapy
For conditions like labral tears and FAI, one of the most debated questions is whether surgery or structured physical therapy produces better outcomes. A randomized controlled trial comparing hip arthroscopy to supervised physical therapy for labral tears in patients over 40 found that the physical therapy group actually displayed better pain and function scores at two years.21PubMed Central. Hip Arthroscopy Versus Physical Therapy for the Treatment of Symptomatic Acetabular Labral Tears in Patients Older Than 40 Years: 24-Month Results From a Randomized Controlled Trial However, a separate trial found that surgical groups outperformed the physical-therapy-only group on most patient-reported outcome measures, and crossover patients (those who started with therapy but eventually had surgery) performed similarly to those who had surgery from the start.22PubMed Central. Hip Arthroscopy vs Physical Therapy for Acetabular Labral Tears: Analysis of a Prospective Randomized Controlled Trial
For FAI specifically, a meta-analysis of three high-quality randomized trials concluded that arthroscopic surgery produced better results than physiotherapy alone.23PubMed Central. Arthroscopic surgery versus physiotherapy for femoroacetabular impingement: a meta-analysis study The picture is clearly more nuanced than “surgery wins” or “therapy wins.” Age, severity of structural damage, activity level, and whether the patient is willing to commit to a rigorous rehabilitation program all influence which path makes the most sense. Many clinicians now start with a structured physical therapy trial and reserve surgery for patients who do not improve. Knowing that crossover to surgery later does not appear to compromise outcomes gives both patients and clinicians some breathing room in making that decision.
Why the Human Hip Is Prone to These Problems
There is an interesting evolutionary backstory to why hip pain is so common. When our ancestors transitioned to walking upright, the pelvis had to become wider and shorter to accommodate the lumbar curve that keeps us balanced on two legs. The hip joint shifted into a much more extended default position compared to other primates.24Journal of Hip Preservation Surgery. Evolution of the human hip. Part 1: the osseous framework These changes were not free. The same evolutionary pressures that optimized our hips for walking and running created the morphological variants that now cause impingement. In men, cam-type morphology at the head-neck junction may represent an adaptation for endurance running, while in women, the wider, deeper socket needed to allow childbirth of a large-brained baby predisposes to pincer-type impingement.25PubMed. Human hip impingement morphology: an evolutionary explanation In other words, the hip joint is an engineering compromise. It handles walking, running, squatting, and pivoting well enough for most of a lifetime, but the design trades that made bipedalism possible also planted the seeds for the impingement, labral tears, and cartilage wear that fill orthopedic clinics today.