[AllKindsOfFun]

I was hoping she’d come back and say what pressure she was using, so I wouldn’t have to speculate, but she didn’t, and she may not even be using a gauged pump. OP if you are reading this, and you know what pressure you were using, please let us know. 

Things like this don’t easily happen accidentally in my own experience pumping at moderate to high pressures, and reading other people’s pumping logs over at the noogleberry forum. As far as I can tell, signs of over pumping typically start with purple discoloration, followed by petechiae (visible burst blood vessels), and finally blisters. I don’t see petechiae in this photo, but that doesn’t mean they aren’t there. She was probably pumping at 150mmhg or more in order to cause this. I’m no scientist and I don’t have a deep understanding of vacuum pressure, but I’ve heard that vacuum pressure does not increase linearly. Meaning that 150mmhg isn’t 7.5 times as “strong” as 20mmhg (pretty much the lowest pressure worth using) like you might imagine. It’s much stronger than that. It’s deep into the painful range IMHO. You can’t accidentally hit that level of vacuum pressure by playing around with pressures that only feel slightly uncomfortable. I think people might be worried that it’s easy to accidentally injure themselves in this way, but I’d say as long as you aren’t completely ignoring strong pain, it’s really not likely to happen. No offense to OP. Some people just have high pain tolerance and  a little too much willpower and motivation. I wish I were that driven to pump sometimes.

That's a very fair point. 

I don't want people to think this happens with casual use. 

I did not use a pressure gauge, but I can tell you I definitely overdid it. 

After googling and some healing time, I learned it's fairly common with cupping pressures (the Chinese medicine practice that uses vacuum cups to stimulate the flow of the chi). Some practitioners seem to believe the cupping blisters are signs of toxins leaving the body. 

This was not the case. This was me being an idiot with very flaccid boobs (breastfed for 12 years + 100# weight loss) and pumping well, well beyond what a system like the noogleberry is capable of.