Osteoarthritis: This is the most common cause of hip pain in adults, especially in those over 50 years old. It is characterized by wear and tear of the joint cartilage, leading to pain, stiffness, and limited mobility.

Trochanteric Bursitis: Inflammation of the bursa over the trochanter, often caused by repetitive friction or direct trauma, leading to pain and tenderness on the outer aspect of the hip.
Tendinitis: Inflammation of the tendons surrounding the hip joint, commonly affecting the gluteus medius or minimus tendons, leading to pain and weakness.
Piriformis Syndrome: Compression of the sciatic nerve by the piriformis muscle, causing pain, numbness, and tingling in the buttock and leg.
Stress Fracture: A small crack in the bone, often caused by overuse or repetitive stress, leading to pain and tenderness in the hip area.

Septic Arthritis: A bacterial infection of the joint, which can lead to severe joint damage and systemic illness if not promptly treated.
Avascular Necrosis: Death of bone tissue due to lack of blood supply, often caused by trauma, steroids, or excessive alcohol consumption, leading to severe hip pain and collapse of the bone.
Hip Fracture: A break in the bone, often caused by trauma or osteoporosis, which can lead to severe pain, disability, and increased risk of mortality if not promptly treated.

Synovial Chondromatosis: A rare condition characterized by the growth of cartilage in the joint, leading to pain, stiffness, and limited mobility.
Paget's Disease: A rare condition characterized by abnormal bone growth and remodeling, leading to pain, deformity, and increased risk of fracture.
Bone Tumors: Rare tumors that can occur in the hip, such as osteosarcoma or chondrosarcoma, which can lead to pain, swelling, and limited mobility.