Understanding the Differences Between Anorexia and Bulimia

Eating disorders are health conditions that affect how you think, eat, and behave. They’re not a “diet” or lifestyle choice. They’re medical illnesses with specific symptoms and treatments. 

Eating disorders affect at least 9% of people worldwide. There are many different types of eating disorders. Two of the most common are anorexia nervosa (AN) and bulimia nervosa (BN).

In this article, we’ll talk about the differences and similarities between AN and BN. We’ll also talk about symptoms and treatments as well as other types of eating disorders. Read on to learn more. 

Quiz: Do I have an eating disorder?

What’s the difference between anorexia and bulimia? 

Anorexia and bulimia are both eating disorders that center on body image and food. The main difference is that most — but not all — people with anorexia have a very low body weight. 

Anorexia nervosa 

Anorexia nervosa (AN) is an illness that causes low body weight and distorted body image. It usually begins during adolescence, but it can happen at any age. 

People with AN:  

• Avoid or restrict food, usually causing a significantly low body weight 

• Have a strong fear of gaining weight 

• Have a negative or distorted view of their body weight, shape, or appearance

Over time, people with AN can also develop physical signs and symptoms:

• Missing periods (amenorrhea)

• Brittle hair and nails

• Fragile bones

• Fine hair growing all over the body (lanugo)

• Muscle weakness

• Severe constipation

• Fatigue

• Organ problems 

As part of their illness, some people with AN also exercise obsessively, binge eat, or purge by vomiting or taking laxatives. 

It’s also important to know that some people with anorexia are not underweight. This is called atypical anorexia. 

Bulimia nervosa 

Bulimia nervosa (BN) is an illness with cycles of binge eating and purging. Most people with BN binge and purge at least once a week. 

• Binging means eating more food than most people would in a similar situation. During a binge, people feel like they can’t stop eating, or they can’t control how much they’re eating. The binge is usually accompanied by feelings of shame or unhappiness.

• Purging is taking action to “balance out” the binge — even though this doesn’t really work. This could mean vomiting, fasting, misusing laxatives or water pills (diuretics), or exercising excessively.

People with BN can also have physical symptoms:

• Scars or calluses on fingers

• Sore throat

• Swollen neck

• Dental problems

• Stomach and gut problems

Just like AN, people with BN can have bodies of all shapes and sizes. If they have a significantly low body weight, they’re usually more likely to be diagnosed with AN. 

What causes anorexia and bulimia?

We don’t know exactly what causes eating disorders. But we do know this: Eating disorders are not caused by “bad habits” or “poor choices.” Just like many other medical conditions, it’s likely that eating disorders are caused by a combination of factors.

Factors that can make you more likely to have an eating disorder include:

Your biology 

• Having a family member with an eating disorder

• Having a family member with mental illness

• Having diabetes Type 1

• Your genes (DNA)

• Your brain function

Your psychology

• Identifying as a “perfectionist” 

• Having another mental health condition

• Having a poor body image 

Your life experiences

• Being exposed to certain cultural messages

• Being bullied or teased

• Experiencing trauma 

• Having parents or caregivers who experienced trauma 

Is treatment the same for anorexia and bulimia?

Generally, yes. Both anorexia and bulimia are treated with a combination of:

• Psychotherapy (talk therapy)

• Nutrition education

• Medications

• General medical care

Medications are usually more helpful for bulimia than for anorexia, but they are used in both.

Treatment can take place in many different settings:

• Doctor’s office

• Health clinic

• Hospital

• Residential treatment center 

• Online (telehealth)

You can read more about these options in our GoodRx guide to eating disorder treatment. 

How do you know if you need inpatient treatment for an eating disorder?

Many people with an eating disorder can be treated successfully as an outpatient. Outpatient treatment means living at home and visiting your doctor’s office as needed.  

But in some cases, a higher level of care is necessary. This could mean going to appointments or therapeutic activities multiple times a week, or even staying overnight for a while in a treatment facility. 

Signs that you need a higher level of care for your eating disorder

If you have anorexia or bulimia, you may need a higher level of care if you:

• Have a BMI lower than 17

• Are having more than eight purging episodes per week

• Have another psychiatric illness, like depression or anxiety 

• Don’t have a good support network

• Are having trouble staying motivated with outpatient treatment

• Are having medical problems 

Eating disorders also cause life-threatening health problems. You may need to be hospitalized for medical care if you:

• Faint or lose consciousness

• Have an electrolyte (mineral) imbalance

• Have an abnormal heart rhythm

• Have a very slow heart rate

• Have a very low body temperature

• Are rapidly losing weight

• Are having suicidal thoughts

Who is most likely to recover from an eating disorder?

People with bulimia may be more likely to recover than people with anorexia. 

There’s some evidence that about 80% of people with bulimia will fully recover, though 20% will have a relapse at some point. Only about 50% of people with anorexia fully recover — though another 30% will have a partial recovery. 

Are there other types of eating disorders?

Yes. There are several other types of eating disorders:

• Binge eating disorder (BED): BED causes people to have repeated episodes of binge eating. These episodes cause feelings of shame, distress, or depression, and they usually happen at least once per week. People with BED usually don’t purge.

• Purging disorder: People with purging disorder purge to try and change their body weight or shape. People with purging disorder don’t usually binge eat.

• Avoidant restrictive food disorder (ARFID): This causes people to limit certain types of food, or amounts of foods. It’s different from anorexia because most people with ARFID don’t have fears about weight or body shape.

• Pica: People with pica eat things that aren’t usually considered food, like dirt, paper, paint, and hair.

• Rumination disorder: This causes people to regurgitate food (bring up swallowed food), which is either re-eaten or spit out.

• Night eating syndrome: This causes people to eat large amounts of food at night, either in the evenings after dinner or during the night while awake. The night eating causes distress, and it interferes with the person’s day-to-day life.

• Orthorexia: Though not an “official” eating disorder diagnosis, orthorexia makes people fixate on certain types of foods or eating patterns. This fixation causes emotional distress. People with orthorexia may spend a lot of time and energy thinking about food ingredients or certain body types and lifestyles. They may also feel anxious if “safe” foods aren’t available to eat.

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Written by:

Sarah Gupta, MD

Sarah Gupta, MD, is a licensed physician with a special interest in mental health, sex and gender, eating disorders, and the human microbiome. She is currently board certified by the American Board of Psychiatry and Neurology.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. A pulmonologist and hospitalist, she practiced and taught clinical medicine at hospitals in London for a decade before entering a career in health education and technology.

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