Do you eat the same thing for lunch every day, eating your food in the same order? Do you find yourself turning on and off light switches or checking buttons and zippers to make sure they are secured? Are you consistently going out of your way to avoid walking on cracks in the sidewalk? If you feel that you must perform rituals such as these over and over again, there’s a chance that you have obsessive-compulsive disorder.

Obsessive-compulsive disorder or OCD is an anxiety disorder characterized by obsessions or compulsions. An obsession is a recurrent and intrusive thought, feeling, idea, or sensation while a compulsion is a conscious, recurrent pattern of behavior a person feels driven to perform. This behavior can be a physical action, such as frequent hand-washing, or a mental act, like counting or repeating words over and over.

OCD was once believed to be rare but recent data has shown that 2 to 3 percent of people, or about 7 million Americans, suffer from this disorder. OCD usually is noticed between the ages of 20 and 30, and 75 percent of those who will develop it show symptoms by age 30.

The exact cause of OCD is unknown but many physicians suspect that it has something to do with faulty brain circuitry. An insufficient level of serotonin, one of the brain's chemical messengers, may contribute to OCD. PET scans comparing the brains of people with and without OCD show differences in brain-activity patterns. People with OCD who take medications that enhance the action of serotonin often show great improvement.

The risk of developing OCD is slightly higher if your parents or other family members have the disorder although researchers have not identified any genes responsible for it. Someone with OCD may also have a biological predisposition to react strongly to stress. This reaction may trigger the rituals and emotional distress characteristic of the illness.

It’s important to understand that there's a difference between being a perfectionist and having OCD. Perhaps you get all of your work done a week ahead of schedule, you compete at sports like a pro and the floors in your house are so clean you could eat off them. That doesn't mean you have OCD. Instead, you may belong to a large group of people who have obsessive compulsive personality traits. This means you hold yourself to a very high standard of performance in all that you do. This behavior contributes to building your self-esteem and success.

These are not the behaviors seen in people with OCD. Behaviors associated with this illness interfere with everyday functioning. Fear of dirt or contamination, concern with order and symmetry and a dread of harming a family member or friend are obsessions commonly associated with OCD, which may also include compulsive actions like counting over and over to a certain number and repeatedly checking that doors are locked.

If you suspect you or someone you know has OCD, it is important to seek treatment immediately. The sooner OCD is treated, the more likely that person will improve the quality of their life and the lives of those around them. Waiting to treat OCD is not appropriate; it should be treated as soon as you suspect that you or someone you care about has the disorder.

If treatment with medications is started, it will like take several weeks before the medication becomes effective before deciding whether they are working. Shame and embarrassment may keep someone from seeking treatment for OCD. But even if their rituals are deeply ingrained, treatments can help. Anti-depressant medications are often recommended as well behavior therapy that involves exposing the patient to a feared object or obsession and teaching him or her different ways to deal with it, rather than performing an anxiety-reducing compulsion.

Obsessive-compulsive disorder is a chronic illness which, like other psychiatric illnesses, has periods of exacerbation followed by periods of relative improvement, though a completely symptom-free interval is generally unusual. With treatment, most sufferers have considerable improvement. Depending upon the severity of the OCD and the patient’s response to treatment, OCD may be treated with medications alone, counseling alone, or a combination of the two. The most effective treatment usually is a combination of medications and counseling.

For those using medications to deal with the illness, it’s important to never vary from the prescribed schedule. Therapy sessions should be attended on a regular basis. And family involvement is also important, those with the disorder should provide friends and relatives with materials that explain OCD and encourage them to join support groups. Such groups can be found in your community or through the Internet.

T. Glenn Pait, M.D., is an associate professor in the College of Medicine at the University of Arkansas for Medical Sciences. “Ask The Doctor” is an information service of UAMS.