2, when there is psychological unhealthy performance, you should see a psychologist. For example, I am afraid of things that are not terrible, such as flowers, water, pens, people and so on. For another example, I can't stop thinking about meaningless little problems in my mind, or washing my hands, and so on.
When there are some strange diseases, you should see a psychologist. For example, sudden paralysis, blindness or deafness due to mental stimulation. Although the corresponding departments in the hospital can't find the disease, they do have strange pain, gastrointestinal discomfort and so on.
Extended data:
As long as people feel unhappy, have problems and don't know how to solve them in life, they can do psychological counseling in principle. Psychological counseling is not only aimed at psychological problems or diseases (although many people's pains and troubles are indeed caused by this), but also at people's wrong thinking in a broader sense.
Each of us has some wrong ideas more or less, such as exaggeration (I didn't do well in this exam, I am an idiot), black or white (if a person loves me, he can tolerate everything about me, otherwise he doesn't love me), and so on. These wrong ideas will make us deal with big or small problems in the course of life. Psychological counseling can help people realize their problems and provide effective steps and methods to help people change themselves.