This paper mainly focuses on Obsessive-compulsive disorder and its related information. The disorder happens all over the world and among all age groups. At the same time, the rate of occurrence of OCD has increased over the years. This article has discussed how OCD has been defined and examined, as well as both aspects of causes, internal and external, from some major factors. OCD patients may struggle with obsessive thoughts and compulsive behaviors, most of which would influence their daily routines and interactions with people. Yet the symptoms wont be unable to reduce. Suggestions such as domestic support and social welfare regarding OCD have been separately analyzed. Meantime, the 3 most common treatments Cognitive behavioral therapy, Exposure and response prevention, and Selective serotonin reuptake inhibitors have been mentioned. What has been realized is the specific root cause for OCD hasnt been found and more causes may have not been discovered yet. To this end, more investigations, possibilities of treatments or combinations may be evaluated in the future to gain further acknowledgements and better.