Obsessive-compulsive disorder (OCD) is a mental health condition that involves distressing, intrusive, obsessive thoughts. These can lead a person to do unwanted, compulsive physical actions, such as repeated safety checks or avoiding germs.

OCD is one of several conditions involving obsessive thoughts and compulsive behavior. Having OCD can significantly affect a person’s quality of life and their well-being.

This article explains OCD’s causes, symptoms, diagnosis, treatment, and tips for living with the condition.

A close up image of a person's hands while speaking with a professional about OCD.-2Share on Pinterest
SDI Productions/Getty Images

OCD is a mental health condition that involves an obsession or compulsion, distressing actions, and repetitive thoughts. It can be challenging for someone with OCD to carry out routine tasks.

Between 1% and 3% of the global population have OCD. This condition is most common between the ages of 18 and 29, and typically symptoms have an early onset.

A person with OCD may:

  • have unwanted thoughts, images, or urges that they feel unable to control
  • experience a significant amount of discomfort, possibly involving fear, disgust, doubt, or a conviction that things must be done in a certain way
  • spend a lot of time focusing on these obsessions and engaging in compulsions, which interferes with personal, social, and professional activities

Is OCD an anxiety disorder?

The fourth edition of the Diagnostic and Statistical Manual (DSM-IV) categorized OCD as an anxiety disorder. However, the fifth edition (DSM-5) reclassified it into a new category called “obsessive-compulsive and related disorders.”

This new category also includes conditions such as hoarding and body dysmorphia.

OCD can affect different people in different ways. According to the charity OCD-UK, five main categories that OCD can fall into include:

Concern with checking

A person with OCD may feel the need to check repeatedly for problems. This might include:

  • checking taps, alarms, door locks, house lights, and appliances to prevent leaks, damage, or fire
  • checking their body for signs of illness
  • confirming the authenticity of memories
  • repeatedly checking communication, such as e-mails, for fear of having made a mistake or offending the recipient

These checks can be time-consuming and significantly affect a person’s daily life, routines, and relationships.

Fears of contamination

Some people with OCD feel a continual, overwhelming need to wash. They may fear that objects that they touch are contaminated, which can lead to:

  • excessive toothbrushing or handwashing
  • repeated cleaning of the home
  • avoiding crowds for fear of contracting germs

Some people may also experience a sense of contamination if they feel someone mistreats or criticizes them. They may try to remove this feeling by washing.

Read about OCD and cleaning.


This involves a person feeling unable to throw away used or useless possessions.

Intrusive thoughts

This involves feeling unable to prevent repetitious unwanted thoughts. These may involve violence, including suicide or harming others.

The thoughts can cause intense distress, but the person is unlikely to act in a way that reflects this violence.

Learn about OCD intrusive thoughts.

Symmetry and orderliness

A person with this type of OCD may feel the need to arrange objects in a certain order to avoid discomfort or harm. For example, they may repeatedly rearrange the books on a shelf.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

Was this helpful?

OCD involves obsessions, compulsions, or both. These can cause distress and interfere with the person’s ability to perform routine activities.


Everyone worries. However, in people with OCD, worries and anxiety can take over, making it hard to carry out everyday tasks.

Common topics of this anxiety include:

  • contamination by bodily fluids, germs, dirt, and other substances
  • violence, such as the fear of acting on an urge to self-harm or hurt others
  • perfectionism, which may involve the fear of losing things or an intense focus on exactness or remembering things
  • responsibility, including a fear of being responsible for a catastrophic event
  • unwanted sexual thoughts, including thoughts about inappropriate activities
  • religious or superstitious beliefs, such as a concern about offending God or stepping on cracks in the sidewalk
  • identity, which may include sexual orientation or gender identity


Not every repetitious behavior is a compulsion. Most people use repetitive behaviors, such as bedtime routines, to help them manage everyday life.

For a person with OCD, the need to perform repetitious behavior is intense, occurs frequently, and is time-consuming. The behavior may take on a ritualistic aspect.

Some common examples include:

  • washing and cleaning, including handwashing
  • monitoring the body for symptoms
  • repeating routine activities, such as getting up from a chair
  • mental compulsions, such as repeatedly reviewing an event

OCD symptoms often start in adolescence, but they sometimes emerge in childhood.

Complications among young people and children with OCD include:

  • low self-esteem
  • disrupted routines
  • difficulty with school and schoolwork
  • physical illness, due to stress, for example
  • trouble forming or maintaining friendships and other relationships
  • other mental health problems

Genetic, neurological, behavioral, cognitive, and environmental factors may all contribute to OCD.

Genetic causes

OCD appears to run in families, suggesting a possible genetic link, which researchers are continuing to investigate.

Imaging studies have also suggested that the brains of people with OCD function with characteristic differences.

Autoimmune-related causes

Sometimes, symptoms of OCD appear in children after an infection, such as:

Clinicians may call this occurrence of OCD symptoms pediatric acute-onset neuropsychiatric syndrome (PANS).

In a child with PANS, symptoms start suddenly and develop over a few days.

Behavioral causes

Learning-based theories suggest that people with OCD learn to avoid fear associated with certain situations or objects by performing rituals to reduce the perceived risk.

The initial fear may begin around a period of intense stress, such as a traumatic event or significant loss.

Once the person associates an object or circumstance with this feeling of fear, they begin to avoid that object or situation in a way that comes to characterize OCD.

Cognitive causes

Another theory is that OCD starts when people misinterpret their own thoughts.

Most people have unwelcome or intrusive thoughts at times, but for people with OCD, the importance of these thoughts becomes more intense or extreme.

Environmental causes

According to a 2018 article, it is still unclear whether stressful life events and trauma may independently cause OCD or act as a trigger for people with a predisposition to the condition.

Environmental events that may potentially contribute to OCD include:

  • complications during pregnancy or delivery
  • age-related reproductive changes
  • socioeconomic problems
  • traumatic injuries
  • a serious illness

Also, OCD may occur alongside post-traumatic stress disorder (PTSD).

Doctors look for the following criteria when diagnosing OCD:

  • the presence of obsessions, compulsions, or both
  • obsessions and compulsions are time-consuming or cause significant distress or impairment in social, occupational, or other important settings
  • OCD symptoms do not result from the use of a substance or medication
  • OCD symptoms are not due to another health issue

The right treatment approach may depend on the person’s symptoms and their severity. Doctors may suggest psychotherapy, medication, or both.

Cognitive behavioral therapy (CBT)

CBT is a type of psychotherapy and a first-line treatment for OCD. It can help a person change how they think, feel, and behave.

CBT may involve exposure and response prevention (ERP). ERP exposes the person to situations and objects that trigger fear and anxiety.

Over time, through a process called habituation, repeated exposure leads to a decrease or disappearance of the anxiety. This teaches the person to resist performing compulsive behaviors.

Individual and group CBT may be effective at treating OCD.


Selective serotonin reuptake inhibitors (SSRIs), which are a type of antidepressant, are first-line medications for OCD. Examples of SSRIs include:

Doctors may prescribe other medications, such as antipsychotics, alongside SSRIs.

Other treatments

Although CBT and SSRIs are first-line treatments, doctors may also discuss other options, including:

Maintaining a healthful lifestyle may help people with OCD manage their condition. This may involve:

Learn more strategies for managing OCD.

If a person with mild OCD does not receive treatment, the symptoms may still improve. However, without treatment, symptoms of moderate or severe OCD do not improve and may worsen.

Treatment can be effective, but it is an ongoing process. Between 25% to 40% of people may continue to experience OCD symptoms following treatment with CBT and SSRIs.

Anyone experiencing OCD symptoms should contact a healthcare professional to learn what treatment options may be available for them.

OCD is a mental health condition characterized by obsessions and compulsions. These obsessions and compulsions can be time-consuming and may affect a person’s daily life and relationships.

OCD typically begins in childhood or adolescence and may occur due to a variety of factors, including genetic and environmental factors or learned behaviors.

People with OCD should speak with a healthcare professional about their treatment options. This may include CBT and SSRIs. Management strategies may also involve relaxation techniques and other lifestyle changes.