What is dysphoria and what can bring it on?

Sadness: "dysphoria" is sadness or feeling depressed. We use it differently than the word "depression." the latter is a formal diagnosis ; requires certain criteria be met. Whereas dysphoria is more of a symptom, descriptive of how someone feels. In other words, you cannot have depression without dysphoric, but you can be dysphoric without having depression. What can bring it on? Too much to list.