Sounds like your mother is dealing with two separate issues. First, the "hip" pain when laying on her sides is a common complaint especially in the elderly. What you think is the "hip" is actually a large bone sticking out on the side called the trochanter. Trochanteric tenderness is frequently a complaint because this area becomes sensitive as the low back degenerates and as the cushioning effect from surrounding soft tissue deteriorates. I frequently suggest the use of mattress toppers made of thick foam or even a foam mattress which can help relieve pressure points and tenderness. Pain and swelling in one leg is cause for concern and raising the possibility of a blood clot. Immediate evaluation by a physician is recommended. Your mother is at risk for developing a blood clot (deep vein thrombosis) because of her recent surgery, her age, and her relative inactivity. For more information about DVT's follow this link: http://www.nhlbi.nih.gov/health/health-topics/topics/dvt/atrisk.html Her primary physician should be able to address both of these concerns that you have. Dr. Christina Lasich, MD