How to Tell the Difference Between Anorexia and Bulimia

By Max. D Gray. Updated: March 25, 2022
How to Tell the Difference Between Anorexia and Bulimia

When the phrase eating disorder is used, people often think of two related, yet different conditions known as anorexia nervosa and bulimia nervosa. It is possible to have had both conditions in a lifetime, but it is less common than having them separately. Although related, there are key differences which need to be understood in order to determine the right course of treatment. This can be tricky as there is inconclusive understanding of how these disorders are caused, even if there are common behavioral patterns for both. oneHOWTO finds out how to tell the difference between anorexia and bulimia, but remember to seek medical advice if you or someone close to you is affected by either condition.

You may also be interested in: What Are the Complications of Bulimia

Anorexia nervosa

In order to find out the differences between the conditions anorexia nervosa and bulimia nervosa, we will detail them both separately and then compare the findings. While they are often used interchangeably, anorexia and anorexia nervosa are not exactly the same. Anorexia used on its own refers to having poor appetite, even if there are different causes. This makes it a symptom, not a condition. Anorexia nervosa is an eating disorder with much more specific physical symptoms which can include:

  • A low BMI (Body Mass Index), often seen as extreme wight loss
  • Yellowing of the skin
  • Brittle hair
  • Fine hair growing over the body (lanugo)
  • Osteoporosis
  • Loss of menstrual cycle
  • Infertility
  • Constipation
  • Irregular heartbeat
  • Elevated liver enzymes
  • Hypotension (low blood pressure)
  • Sensitivity to cold
  • Fatigue
  • Aches and pains in muscles
  • Over-exercising

While specialists can't determine the exact cause of anorexia nervosa, it is known that a person's psychological condition can have a bearing. This can result in the following psychological symptoms (although it is important to remember that the physical and psychological symptoms do have correlations):

  • Depression
  • Anxiety
  • Insomnia
  • Fear of gaining weight
  • Obsession with food, counting calories, methods of food preparation, etc.
  • Body dismorphia (where the perception of the body does not correlate to its actuality)
  • Mood swings
  • Introspection and self-seclusion
  • Using laxatives or diet pills to purge food

Suspected causes of anorexia nervosa

While we have stated that it is difficult to determine the exact cause of anorexia nervosa, there are many related factors. The first is genetic. There is significant research to pinpoint a relation between anorexia nervosa and hereditary causes[1]. According to the study, the heritability rate (i.e. the rate at which anorexia is inherited through genetics) could be as much as 58%.

Other physical conditions can also have a bearing, often seeming to have anorexia nervosa as a resulting symptom. These can even include childbirth as both the psychological impact and related physical disorders have been known to result in anorexia nervosa. Gastrointestinal issues can also play a hand in people developing the condition. Coeliac disease, irritable bowel syndrome and other related conditions can lead to problems controlling weight and, if they get out of hand, can result in anorexia nervosa. However, these issues can be very complicated and can include many different psychological and physiological factors.

Anorexia nervosa is more prevalent in women than in men[2]. There are many potential reasons for this trend, but one possible factor is the sociological issues relating to it. Firstly, it is hard to tell whether anorexia nervosa is a recent condition or whether it has simply only been recognized as a condition relatively recently.

Its first official diagnosis of anorexia nervosa was in 1873 by William Gull (one of Queen Victoria's personal physicians), but there are people in prior history who seem to have had the condition and been diagnosed after the fact. Public perception, however, has increased since the latter half of the 20th century.

As anorexia nervosa is considered an obsessive need to control one's weight, it is possible that the increase of material which shows a certain type of body image has had a bearing on diagnoses of the condition. The theory is that there is a societal pressure to have a certain body type, proliferated through magazines, advertisements and a general exaltation of those with a thinner body type. This is supported by online communities of people who encourage each other's anorexia through forums and personal testimonials. The websites are referred to as "pro-ana" meaning pro-anorexic[3].

Pro-ana websites highlight the psychological nature of the condition. When someone with anorexia nervosa obsesses over their weight, they will do so to the extent that not only do they end up losing weight, but they see this extreme weight loss as being a positive thing for their body. People suffering from the condition often use their weight loss as a means to control their anxieties, depression or other related mental conditions. It means that, even when everybody else can see that they are seriously underweight and unwell, they cannot.

The biggest problem this raises is the one which concerns treatment. Treatment of anorexia nervosa is not as simple as feeding the person until they regain weight. It needs to be treated both physically and psychologically. If not, then the person is unlikely to keep up treatment. In fact, even the dramatic step of hospitalization may not be enough to help perceptions as the relapse rate of people who have done so is 35%[4].

Moreover, complications surrounding anorexia nervosa can make the condition even more difficult to treat. This is because not only is relapse a significant factor, but the condition has comorbidity (i.e. two conditions happening simultaneously) with OCD (obsessive compulsive disorder), depression and other related issues. One further complication is the possible link between anorexia nervosa and addiction as a study in 2015 shows there are parallels between the two[5]. This means that continuing the practices which lead to anorexia nervosa are similar to those who are addicted to certain substances, complicating treatment further.

How to Tell the Difference Between Anorexia and Bulimia - Suspected causes of anorexia nervosa

Bulimia nervosa

Unlike anorexia nervosa, the terms bulimia and bulimia nervosa are actually interchangeable with no diagnostic difference between them. However, as you will see, there are many similarities as well as differences between bulimia and anorexia nervosa. The main similarity between the two is that both anorexia nervosa and bulimia nervosa are to do with obsessions over how we eat. The main difference is how this obsession results in the physical alteration to the individual. The symptoms of bulimia nervosa are as follows:

  • Bingeing on food, followed by purging
  • Gastric reflux
  • Worn dental enamel from vomiting
  • Irregular heartbeat
  • Swelling of the esophagus
  • Constipation
  • Ulcers
  • Swollen salivary glands in the cheeks
  • Scars or calluses on knuckles from inducing vomiting
  • Dehydration
  • Dry skin and brittle hair
  • Seizures
  • Fatigue
  • Low blood pressure
  • Problems with menstrual cycle
  • Muscle cramps
  • Over-exercising

As you can see there are some similar physical symptoms to anorexia nervosa as well as some which are more specific to bulimia. The same can be seen with the psychological symptoms of the latter condition:

  • Depression
  • Anxiety
  • Insomnia
  • Low self-esteem
  • Body dismorphia
  • Obsession with food and extreme consciousness of weight
  • Body dismorphia (where the perception of the body does not correlate to its actuality)
  • Mood swings
  • Introspection and self-seclusion
  • Using laxatives or diet pills to purge food
How to Tell the Difference Between Anorexia and Bulimia - Bulimia nervosa

Suspected causes of Bulimia nervosa

Similar to anorexia nervosa, it is believed there is a hereditary predilection for having bulimia nervosa. There are also some studies which see a correlation between addiction and bulimia nervosa. The research seems to link it to dopamine receptors in the brain which are triggered during bingeing and purging.

Bulimia nervosa is not, however, limited to bingeing and purging food. Many people try to control their weight and body image through over-exercise, using laxatives or only drinking water.

Similar societal pressures appear to have an effect on bulimia nervosa. Those who have the condition often have an obsession with body image and will judge themselves poorly against others. What is significantly different between the two conditions is the fact that those with bulimia nervosa are often of a normal weight or are even slightly overweight. Only about 19% of bulimics undereat, so it is uncommon to see bulimics who are underweight. In fact, according to Dr. Wade Berrenettini in the journal Psychiatry (Edgmont), "abnormally low body weight excludes a BN (bulimia nervosa) diagnosis"[6]. However, according to the same study, 25% to 30% of people with bulimia nervosa have had anorexia nervosa in the past.

This goes to show that anorexia nervosa and bulimia nervosa have many similarities, mainly the obsession with body weight, a compulsion to change body image and having related psychological issues which tie in an exacerbate the condition. Depression, anxiety and even addiction are common comorbidities of bulimia nervosa.

Differences between anorexia and bulimia

When we compare the two eating disorders, the main difference between anorexia nervosa and bulimia nervosa is linked to patients' behaviour to control their weight. On the one hand, people with anorexia exhibit compulsive controlling behaviour to lose weight. They are consumed with analyzing and controlling everything they consume and go as far as not eating anything all day.

In contrast, patients with bulimia nervosa exhibit more anxious behavior and less of a controlling attitude. They, in fact, can lack any control over their daily intake. This can lead to following extreme diets like going one day without eating, then eating a large amount of food (binge eating). Consequently, they compensate for these binges by inducing vomiting or taking laxatives. Often this is as a means to get rid of the guilt and shame they feel about themselves when overeating.

Here are some more specific differences between anorexia nervosa and bulimia nervosa:

  • Use of medication: we have discussed the need for psychological treatment of both anorexia and bulimia. Some physical treatments for anorexia nervosa are to combat the symptomatic aspects of the condition. According to 2005 study[7], "none of the medicines available have been shown to be very effective on their own in the treatment of anorexia nervosa". Once the physical symptoms, such as weight gain, have been helped, there may be a cause to treat with antidepressants in order to prevent relapse.In treating bulimia nervosa, there is more success with drug treatments such as Prozac, Tofranil or Topomax (an anticonvulsant). These help satiate the desire for bingeing and purging and help with the depression related symptoms of the condition. This highlights one of the key differences. While bulimia nervosa is a serious condition which requires medical assistance, and can even be fatal, anorexia nervosa is considered more severe. This is due to the rates of hospitalization and death. Eating disorders in general have the highest rates of mortality for mental illnesses, but anorexia is more fatal than bulimia.

  • Recovery rates: supporting the severity of anorexia nervosa in comparison to bulimia nervosa is the rate of recovery. In women with anorexia nervosa, full recovery rates are 33%, compared to the same with bulimia nervosa which is 74% (statistics from 1999)[8]. Again, this is not to downplay the seriousness of bulimia, but to show how much of a total hold anorexia nervosa can have on an individual.
  • Body shape: this is a key difference between the two conditions as those affected by anorexia nervosa are often noticeably thing and emaciated. Those with bulimia nervosa don't necessarily tend to be as thin. However, the insides in someone affected by bulimia are more likely to have suffered specific trauma from vomiting. This includes dental wear, significant inflammation of the digestive tract and abrasions on the skin.
  • Relation to food: while some with anorexia nervosa may binge, it is not a common trait with all cases. This goes back to the idea of addiction and eating disorders. A 2013 study comparing eating disorders and addiction claims those with anorexia nervosa "find that food is anxiety provoking and starvation comforting"[9]. Those with bulimia tend to have a different approach to food. While it is indeed anxiety provoking, especially when people with bulimia feel they have overeaten, they still want food. They may even be addicted to it. This is what often leads to purging or counteracting eating with something like obsessive exercise.

Having any eating disorder is not going to be healthy for mind or body. But controlling and treating anorexia nervosa has different considerations than treating bulimia nervosa. What is true of both cases is need for a dual plan in treating the physical symptoms while providing therapy to help change the psychological compulsions for treating the body in such a way.

If you or someone you know is affected by an eating disorder and you would like some help, please call the National Eating Disorder helpline on (800) 931-2237 in the USA and 1-866-633-4220 in Canada. In the UK there are two numbers, 0808 801 0677 for adults and 0808 801 0711 for youths.

This article is merely informative, oneHOWTO does not have the authority to prescribe any medical treatments or create a diagnosis. We invite you to visit your doctor if you have any type of condition or pain.

If you want to read similar articles to How to Tell the Difference Between Anorexia and Bulimia, we recommend you visit our Mental health category.


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