Some thoughts that get stuck to the mind that badly, which forces us to keep thinking or having result in contemplating with that. It might be any past incident, curiosity to be kept in touch, addiction for something, fear of losing etc.
We don’t even have idea of how much our time gets passed thinking about same that leads us to nowhere and at the end of day we realize being caught in unnecessary and unwanted thoughts resulting in obsession. It affects our day to day lives, makes us away from important things which have to be focused, separates ourselves from people around, sleeplessness and makes us so obsessive about that particular thing, making us unable to deal with the main issues.
Source: Panic and anxiety
There are some ways to get rid of these unwanted thoughts or to avoid obsession:
Planning your daily schedule:
By making your whole day schedule so tight and busy, so you don’t even get spare time to have other thoughts behind you have planned for. You may contribute in doing things you always love to do for example hanging out with friends, whatever your hobbies, starts interacting with people who bring new things in your life to think about, taking interest in whatever happening around for some time that helps you to faint towards your recurring unwanted thoughts.
Devoting small time in meditation:
Meditation is the best practice to get free from thoughts causing anxiety. It leads our mind nowhere but realizes mind best to be in present moment. The same makes our mind focused inside at particular point but not focused in external world. It keeps mind relaxed and expands the way of thinking.
Thinking of drawbacks having unwanted thoughts:
Having unwanted thoughts somewhere reduces your confidence level, sleeplessness etc. It makes your thoughts confined to some level. You may start relating everything with the same issue. It happens forcefully by mind itself which results in having pact with yourself not to keep on thinking.