Obsessive-compulsive thinking is the main manifestation of OCD. The specific clinical manifestation is repeated thinking, repeated worrying and repeated doubting, such as repeatedly thinking about the meaning of one’s existence, repeatedly suspecting that one’s hands have touched something dirty, repeatedly worrying about what kind of disease one has, or even repeatedly thinking about some useless philosophical problems, or repeatedly worrying that one will jump when one is standing on a high place, or repeatedly worrying that one will jump when one sees a knife Worry that you will hurt yourself or others with a knife. If the above compulsive thinking exists, there may also be counter-compulsive problems, that is, you know that these compulsive thoughts are useless and meaningless, and you want to fight it and stop it, but this fight will cause a greater reaction, such as pain, irritability, depression, etc. If you already have a compulsive thinking problem, you must actively treat it, preferably with cognitive behavioral therapy.