Jung talked about midlife crises as happening in the mid-to-late 30s until the early 40s. It's when you've lived a certain amount of your life and had a chance to reflect on your life. In our society, there's a good chance that you've been married or are married, or have had relationships of substance. You may not be satisfied with your work or relationships or feel general dissatisfaction. Things aren't necessarily falling apart. It may be as simple as feeling a little lackluster. Some of these things can surface from feelings that arose but were not addressed years ago.
It can look much more serious though. There may be problems from losing a partner, a partner being sick with cancer, or losing a job and a source of income.
Quarter life crisis may be with younger generation, mid 20s to mid 30s. It's common that an individual hasn't been able to find a good job and isn't able to live the life they dreamed.
I generally use crisis when describing these circumstances to the extent they're easily understandable. I prefer shying away from "crisis" and instead using the word "transition."
Something does not have to be what we think of as a crisis to need addressing. It's better that it's not, that it hasn't gotten to that level. It will be more manageable. It may mean less serious changes and less serious struggle. It's often something we're not addressing. Something we're ignoring, purposefully or unpurposefully. Maybe changing a job or career, ending a relationship, or addressing an uncomfortable topic in a relationship.
This may manifest itself in the form of a broad or general anxiety.
The goal is breaking it down in a more localized, digestible way, as opposed to trying to address the broader picture. What's so overwhelming is the thought that everything is lackluster, falling apart. That it is not what is wanted. Break things down into small pieces to create new perspective and avoid overwhelming yourself. Perspective is important. Being aware of your perspective and ways you may catostrophize situations can help understand what's actually going on and allow it to be addressed in a pragmatic way.
Depth work can help in exploring motivations and interests. It may bring consciousness to how other aspects of our self are neglected and how we only lived part of our lives or part of our potential.