Hip and lower back pain can be caused by many different underlying conditions, such as fractures, arthritis, infections and muscle strains, according to MedlinePlus. Hip pain may be a symptom of a back problem, not a hip problem.
Problems in the bones or cartilage of the hip can cause hip pain, such as hip fractures, arthritis, infection in the bones or joints, and osteonecrosis of the hip. Other causes of hip pain include bursitis, hamstring problems, a strained hip flexor or groin, and hip-impingement and snapping hip syndromes, MedlinePlus explains.
Lower back pain is frequently caused by sudden injury to ligaments and muscles supporting the back, states MedlinePlus. However, lower back pain can be a symptom of a more serious condition. Sudden lower back pain can be caused by compression fractures, sciatica, spinal stenosis, spine curvatures, or ruptured or herniated disks. Additional causes of sudden lower back pain include spasms, strains or tears in back muscles.
Sometimes, more chronic conditions can cause lower back pain, such as a leaking abnormal aortic aneurysm, arthritic conditions, infections of the spine, and kidney infections or kidney stones. Lower back pain can also be caused by problems related to pregnancy or medical conditions that affect reproductive organs, according to MedlinePlus.