Can pinched nerve in lower back cause edema? Pain specialist says I have pinched nerve causing low leg issue. But leg has edema (noted by therapist).

Have a full exam. Your pinched lumbar nerve may be part of the picture but so might other issues that may be hiding behind your chronic pain. Have a good full (lab work, too) exam to discover the role other issues might play. Pay some attention to your fluid intake/output amounts to report to the Dr. Endocrine, urology, bariatric, cardiac and other issues can result in swelling symptoms. Exam may lead to treatment.
Indirectly. If the leg is painful & U limp badly, the leg can swell since the muscles R not functioning properly. .