Put your hand where it hurts. That single request sorts out more "hip pain" than any scan, because the hip joint and the lower back both send pain into the same neighbourhood, and patients — quite reasonably — call all of it the hip.

True hip joint pain is felt in the groin

The hip is a ball-and-socket joint that sits deep in the groin, not at the side of the pelvis where the bony point is. Pain from the joint itself is felt in the front — in the groin crease — and sometimes runs down the front of the thigh to the knee. It is worse on twisting, getting in and out of a car, putting on socks, and after walking. Sitting is usually comfortable.

Pain at the side of the hip is usually soft tissue

Pain over the bony point on the outer side, worst when lying on that side at night or after standing on one leg, is most often the tendons and bursa around the hip (trochanteric bursitis or gluteal tendinopathy). It is common, especially in women over 50, and it is treated with exercises and sometimes an injection — not with anything done to the joint.

Pain in the buttock or down the back of the leg is usually the back

The lumbar spine refers pain to the buttock, the back of the thigh and sometimes below the knee. Tingling, numbness, or pain that changes with sitting, coughing or bending forward all point to the spine rather than the hip. A worn hip can coexist with a worn back — in that case an examination decides which one is producing the symptoms you actually mind.

The two-minute self-check

  • Groin pain, worse on twisting or putting on shoes: probably the hip joint.
  • Pain on the outer side, worst lying on it at night: probably tendons or bursa.
  • Buttock or back-of-thigh pain, tingling, worse sitting or bending: probably the back.
  • Sudden inability to bear weight after a fall, at any age: an emergency department, today.

Why it matters

The treatments diverge completely. A worn hip joint may eventually need a replacement; a tendon problem needs a strengthening programme; a back problem needs neither. Getting the diagnosis right first is what stops people spending months on the wrong treatment.

The hip is in the groin. If the pain is not in the groin, start by doubting the hip.