Hematoma or Contusion: This is the most likely diagnosis given the history of a fall, which can cause direct trauma to the soft tissues around the hip, leading to bruising and swelling.

Hip Fracture: A fall can also result in a fracture of the hip, especially in older adults or those with osteoporosis. The fracture could be of the femoral neck, intertrochanteric, or subtrochanteric region.
Soft Tissue Injury: This includes injuries to muscles, tendons, or ligaments around the hip, which can occur from the fall and present with bruising and swelling.
Dislocation or Sprain: Though less common, a severe fall could potentially dislocate the hip or cause a sprain to the surrounding ligaments.

Pelvic Fracture: While less common than hip fractures, pelvic fractures can occur from significant trauma and are critical to identify due to potential complications such as bleeding or injury to pelvic organs.
Vascular Injury: Injury to the femoral artery or vein could occur from a fracture or severe trauma, leading to significant bleeding or circulatory compromise.
Nerve Injury: Damage to nerves in the hip area, such as the femoral nerve or sciatic nerve, could result from the fall and lead to numbness, weakness, or paralysis.

Osteonecrosis: Though not immediately apparent after a fall, osteonecrosis of the femoral head could be a late complication of a hip fracture or dislocation, especially if there is a disruption of the blood supply to the bone.
Infection: In rare cases, an open wound from the fall could become infected, leading to cellulitis, abscess, or osteomyelitis.
Tumor: A pathological fracture through a pre-existing bone tumor could present with bruising and swelling after a minor fall, though this would be extremely rare and typically associated with other symptoms such as weight loss or night pain.