I have fluid in my lower back and have had so for a few months, following a laparoscopy. It really hurts to twist in certain ways and sometimes for no reason at all. Sitting feels better. It is all lumpy under the skin and moves around. It seems to be getting more. I was told by a muscular skeletal masseuse that its definately fluid. Do I need to go to the doctor? It does seek to be getting worse.
You need to go for check by a doctor, if it is some cyst, it is inflamed causing pain and needs definitive treatment. Try some ibuprofen 400 mg thrice after meals in meantime. Lower back pain also needs to be checked for the cause in spine by an orthopedics doctor, who might ask for X-ray/MRI as per necessity on physical examination