Obsessive compulsive disorder - OCD treatment and therapy from NOCD

Illness Anxiety Disorder vs. OCD

By Grant Stoddard

May 12, 20238 min read minute read

Reviewed byPatrick McGrath, PhD

Are you constantly worrying about your health? Do you spend time each day checking your body for signs of illness or scouring the internet for medical information? Have your friends or family members ever called you “OCD” or a “hypochondriac”? 

Being aware of how well your mind and body are functioning is a key part of staying healthy, but there’s a point at which your health anxieties can become, paradoxically, unhealthy. For people with Illness Anxiety Disorder (IAD) or health/contamination themes of Obsessive-Compulsive Disorder (OCD), health-related worries and attempts to avoid or alleviate them are often all-consuming. 

Excessive health-related worries and behaviors show up in both conditions, but as you may understand from researching potential health issues online, similar symptoms can have distinct underlying causes and often need to be treated differently.

This article will explore the similarities and differences between IAD and OCD and discuss the proven most effective way to manage the symptoms of these conditions and break their grip on your life.  

Illness Anxiety Disorder (IAD)

Illness Anxiety Disorder (IAD), formerly known as hypochondriasis, is a mental health disorder characterized by excessive worry or preoccupation with having or getting a serious illness. To meet the criteria needed for a diagnosis of IAD, a person’s fears must persist even when they’re reassured by professionals that they are healthy.

According to the DSM-5, the prevalence of IAD is estimated to be around 1-5% in the general population. In the US alone, that means that several million people suffer from the condition. No single, exact cause of IAD is known, but research suggests that genetic, psychological, and environmental factors may all contribute to its development.

Symptoms of IAD can include preoccupation with bodily sensations, such as pain or discomfort, excessive health-related behaviors, such as frequent doctor visits, and persistent anxiety about health. Subtypes of IAD include care-seeking, in which people seek out medical care for perceived illnesses, and care-avoidant, in which people avoid medical care due to fear of finding out they have an illness.

Are hypochondriasis and IAD the same thing? 

Hypochondriasis—along with the related words “hypochondriac” and “hypochondria”—is an outdated term for IAD that was used in previous versions of the DSM. The term is no longer used due to its negative connotations, as it implies that people are exaggerating or faking their symptoms. The term IAD better reflects the nature of the disorder, which involves excessive worry and fear related to health.

Obsessive-Compulsive Disorder (OCD)

Obsessive-Compulsive Disorder (OCD) is a mental health disorder characterized by unwanted and intrusive thoughts that cause distress, leading to compulsive behaviors done in an attempt to feel better or avoid a feared outcome. According to the National Institute of Mental Health (NIMH), OCD is estimated to impact around 1-2% of the general population at some point in their life.

The “OCD cycle” is a pattern of thoughts, feelings, and behaviors common among people with Obsessive-Compulsive Disorder (OCD). It begins with an intrusive and distressing thought, image, or urge, often related to a particular fear or worry. This thought triggers intense anxiety, fear, or discomfort, which is difficult to tolerate.

To reduce this discomfort, people with OCD engage in compulsive behaviors or mental rituals, such as counting, checking, washing, or repeating phrases. These behaviors may temporarily relieve distress, but they ultimately reinforce obsessive thoughts and make fears worse.

Break the OCD Cycle

Over time, the OCD cycle can become more intense and time-consuming, leading to significant interference in a person’s daily life. For example, a person with OCD may spend hours each day engaging in rituals or avoiding situations that trigger their obsessions. This can lead to social isolation, impaired work or academic performance, and difficulty maintaining relationships.

People’s fears and compulsions in OCD can involve a wide range of themes. Some of the more common subtypes include: harm, sexual content, false memories, gender and sexuality, order and symmetry, and health concern and contamination, involving fears about the prospect of being—or becoming—ill and engaging in compulsive behaviors in response. 

Health Concern and Contamination OCD explained

Health Concern and Contamination OCD are the subtypes of OCD most likely to be confused with IAD. As their names suggest, they are characterized by excessive and persistent fears about one’s health. People with Health Concern OCD may become preoccupied with the fear of having a serious illness, despite medical reassurances that they are healthy. People with Contamination OCD have an excessive fear of germs, dirt, or contaminants that could make them or others ill. 

Compulsions associated with Health Concern OCD may include constantly checking one’s body for signs of illness and seeking reassurance from healthcare providers. People with Contamination OCD, meanwhile, may engage in excessive hand washing or avoid public spaces. 

These fears and compulsions can significantly interfere with daily life and cause significant distress and anxiety, causing people to isolate themselves from others and even become completely housebound.

Similarities between IAD and OCD

Let’s review what IAD and OCD have in common.  

Obsessive thoughts: Both IAD and OCD involve persistent and intrusive thoughts that cause significant distress or impairment in daily life.

Anxiety and fear: Both IAD and health concern OCD are characterized by anxiety and fear related to the preoccupation or obsession, causing significant distress or impairment in daily life.

Time-consuming behaviors: Both IAD and health concern OCD involve time-consuming behaviors related to these preoccupations or obsessions, sometimes occupying every part of a person’s day.

Impact on quality of life: Both IAD and health concern OCD can cause impairment in daily activities, relationships, and overall well-being.

Differences between IAD and OCD

As we’ve learned, obsessions and compulsions define OCD. At first glance, illness anxiety disorder might also appear to involve both these symptoms; however, Dr. Patrick McGrath, psychologist and Chief Clinical Officer at NOCD, explains that this resemblance can be deceptive.

“With OCD, you’ll see very ritualistic kinds of behaviors. They may have to do something exactly the same way or check it a certain number of times or something like that,” says Dr. McGrath. “In illness anxiety disorder, they might just run to the bathroom and check quickly to see if that spot of concern has got any bigger. They’re not taking any kind of ritualized approach to doing something about it. They’re just assessing to see what, if anything, has changed.”

Let’s consider two examples of people experiencing these conditions to help us learn to distinguish IAD and OCD. 


John is a 32-year-old man experiencing persistent anxiety and fear related to his health. He worries constantly about having a serious illness, such as cancer or heart disease, and frequently seeks medical care to reassure himself that he is healthy. Despite medical reassurance, John continues to worry and experience significant distress related to his health.


Sarah is a 28-year-old woman experiencing intrusive thoughts related to becoming ill. After becoming fixated on thoughts of having a number of different illnesses, she takes her temperature twice every day, repeating “I am okay” to herself as she waits. When she returns from work, she checks various parts of her body for abnormalities, scans her face in the mirror, and takes her blood pressure. Many days, she returns to each of these “tests” one or two more times, afraid that she may have missed something.

Comparing the two cases

Both John and Sarah experience significant distress related to their thoughts and engage in behavior intended to quell their anxiety. While John seeks professional reassurance in an ad hoc manner, Sarah does very specific behaviors in particular ways. Her behaviors are ritualized, while John’s are not. John will later be diagnosed with  IAD. Sarah, on the other hand, will be diagnosed with OCD. 

Despite this main point of difference, however, the best treatment for both disorders happens to be the same.   

Exposure and Response Prevention (ERP) therapy for IAD and OCD

Exposure and Response Prevention (ERP) therapy is a type of cognitive-behavioral therapy that is highly effective in treating both OCD and Illness Anxiety Disorder (IAD). 

ERP involves gradually exposing you to situations that trigger obsessive thoughts or fears while preventing you from engaging in compulsive or avoidant behaviors. ERP aims to help you develop more other ways of coping with your distress that reduce the power of your obsessive fears, rather than reinforcing them and making them stronger over time

In ERP, you’ll be exposed to situations that trigger your anxiety, such as reading about a rare illness online, and then preventing yourself from engaging in checking your body for signs of it for a certain period of time. As you progress through treatment, you and your therapist will move on to more difficult exposure exercises, continuing to resist compulsions as you go.

Soon, you’ll learn to tolerate the distress associated with uncertainty and develop more reasonable approaches to keeping yourself healthy. This will allow you to live life the way you want, according to your own knowledge, values, and decisions, rather than being ruled by fear and compulsive behaviors. 

Getting help 

If you think you might have OCD and are interested in learning how it’s treated with ERP, I encourage you to learn about NOCD’s accessible, evidence-based approach to treatment with the NOCD Care team to learn how it can help you. 

All of our therapists specialize in OCD and receive ERP-specific training. You can also get 24/7 access to personalized self-management tools built by people who have been through OCD and successfully recovered.

We specialize in treating OCD

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