I took Tramadol occasionally over a number of months for pain from Kidney Stones...
As a pain killer, they were excellent...twenty minutes or so after taking the pill, a feeling of utter relaxation spread from the feet upwards!!
Two side effects though...with the drug taken, I just could not sleep...although I didn't really care, given the sense of relaxtion that was induced...
Secondly, I always suffered nausea for the next day or two...nothing serious, but enough to put me off food for the day.
Hope this helps.