I remember my mom washing her immersion blender. She always left it plugged in and turned it on in the dish water, so the blades get clean. One day, she was trying to wash the cap at the same time and caught her index in the immersion blender. She turned down my advice to go to the ER, she rather had me tape the finger. It was of no use, gauze would just instantly get soaked and started dripping blood. But she still didn't feel the need to go to the ER because "that will heal, I had worse".
Spoiler alert, when she couldn't sleep that night because of throbbing pain, she asked me to take her to the ER. They were pretty mad at her and asked her why she didn't come instantly. 6 stitches and a load of antibiotics.