Hi! First-time posting here. I've been using the Aneros MGX for a few years now, but have never had a super-O.
Recently though, I've noticed that getting aroused makes the left-side "tubing" in my scrotum swell, with an occasional ache. Obviously, Aneros sessions are very arousing, so after a session, the left side of the scrotum gets really swollen. The swelling subsides a bit when ejaculating, but subsides mostly with an arousal-embargo (physical and mental) of a couple of weeks.
The swelling also occurs if I practice the suggested muscle contraction exercises.
So my question is if this is a normal side-effect which would go away if I reach a super-O, or if it reflects some sort of "blockage" on my part? Or does it sound like a health issue?
@alex85 this does not sound good at all. I would halt all activities and check with my doctor. Do not take chances, life is too short. Good luck.
@alex85 I concur with GGringo. Aneros can foster intense arousal (even without an erection), which can mask pain. It's more about finesse than force - took me some embarrassing moments to realize that. That said, Aneros may not be the source of the problem, but somehow exacerbates it. Aneros aside, that you have the same issue with contraction exercises indicates something that isn't working right.
The swelling also occurs if I practice the suggested muscle contraction exercises. So my question is if this is a normal side-effect which would go away if I reach a super-O, or if it reflects some sort of "blockage" on my part? Or does it sound like a health issue?
I'm not a doctor so what I say may be totally incorrect but what you describe does not sound normal to me. While vaso-congestion leading to temporary organ swelling due to sexual arousal is normal and to be expected, associated pain seems to be indicative of a non-normal condition. I think it is erroneous to believe this effect will abate by achieving a Super-O and the fact you are experiencing this while going Anerosless would indicate there is something else going on in your body which may need to be evaluated. It is probably nothing serious but I'd recommend you have a doctor evaluate this rather than expect those of us on the forum to diagnose your condition.
Good Vibes to You ! 
Yeah I'd wanna rule out medical, like inguinal hernia or testicular torsion. Call sooner than later. Could be just lymphatic. No further aneris until u have the medical clear. Seems arousal may cause the sudden symptoms. Also are you doing ejaculate denial. There is too much of a good thing sometimes.
An appt. with a good urologist is just what the doctor ordered! Good luck!