Diagnosing OCD beings with a physical exam to help rule out other problems that could be causing symptoms and check for any related complications. Lab tests may include a complete blood count, a check of thyroid function, and screening for alcohol and drugs. A psychological evaluation includes discussing thoughts, feelings, symptoms and behavior patterns, and may include talking to the patient’s family or friends (with the patient’s permission).

OCD symptoms can be similar to those of obsessive-compulsive personality disorder, anxiety disorders, depression, schizophrenia, or other mental health disorders. It’s possible to have both OCD and another mental disorder. OCD usually includes both obsessions and compulsions, but it’s also possible to have only obsession symptoms or only compulsion symptoms. Patients may or may not realize their obsessions and compulsions are excessive or unreasonable, but they take up a great deal of time and interfere with their daily routine and social or work functioning.


Obsessions are repeated, persistent and unwanted thoughts, urges or images that are intrusive and cause distress or anxiety. Patients might try to ignore them or get rid of them by performing a compulsive behavior or ritual. These obsessions typically intrude when they’re trying to think of or do other things. Obsessions often have themes to them, such as: fear of contamination or dirt; needing things orderly and symmetrical; aggressive or horrific thoughts about harming oneself or others; or unwanted thoughts, including aggression, or sexual or religious subjects.


Compulsions are repetitive behaviors or mental acts that patients feel driven to perform, meant to prevent or reduce anxiety related to obsessions or prevent something bad from happening. However, engaging in the compulsions brings no pleasure and may offer only a temporary relief from anxiety. Patients may make up rules or rituals to follow that help control anxiety when having obsessive thoughts. These compulsions are excessive and often not realistically related to the problem they’re intended to fix. As with obsessions, compulsions typically have themes, such as: washing and cleaning, checking, counting, orderliness, following a strict routine, and demanding reassurances.

OCD usually begins in the teen or young adult years. Symptoms begin gradually and tend to vary in severity throughout life. Symptoms generally worsen when patients experience greater stress. Usually considered a lifelong disorder, OCD can have mild to moderate symptoms or be so severe and time-consuming that it becomes disabling.