What is Bulimia Nervosa?

Updated: Oct 6, 2020

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Bulimia nervosa (BN) is binge eating, followed by purging. Purging is anything that overcompensates for consuming large amounts of food and can include excessive exercise, vomiting, fasting, unnecessary use of laxatives and diuretics, or enemas.

Diagnosis Criteria

Credit to NEDA.

  • Recurring episodes of binge eating, characterized by the following:

  • Eating an excessive amount of food for body size in a small amount of time

  • Feeling a lack of control while eating

  • Reactionary behavior to prevent weight gains such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise.

  • Episodes must occur once a week for three consecutive months

  • A negative perception of body and weight

  • Events don't necessarily need to occur with anorexia nervosa


Credit to NEDA.

Emotional and behavioral

  • In general, behaviors and attitudes indicate that weight loss, dieting, and control of food are becoming primary concerns

  • Evidence of binge eating, including the disappearance of large amounts of food in short periods or lots of empty wrappers and containers indicating consumption of large quantities of food

  • Evidence of purging behaviors, including frequent trips to the bathroom after meals, signs and/or smells of vomiting, presence of wrappers or packages of laxatives or diuretics

  • Appears uncomfortable eating around others

  • Develops food rituals (e.g., eats only a particular food or food group [e.g., condiments], excessive chewing, doesn't allow foods to touch)

  • Skips meals or takes small portions of food at regular meals

  • Disappears after eating, often to the bathroom

  • Any new practice with food or fad diets, including cutting out entire food groups (no sugar, no carbs, no dairy, vegetarianism/veganism)

  • Fear of eating in public or with others

  • Steals or hoards food in strange places

  • Drinks excessive amounts of water or non-caloric beverages

  • Uses excessive amounts of mouthwash, mints, and gum

  • Hides body with baggy clothes

  • Maintains extreme, rigid exercise regimen – despite the weather, fatigue, illness, or injury—due to the need to "burn off" calories

  • Shows unusual swelling of the cheeks or jaw area

  • Has calluses on the back of the hands and knuckles from self- induced vomiting

  • Teeth are discolored, stained

  • Creates lifestyle schedules or rituals to make time for binge-and-purge sessions

  • Withdraws from usual friends and activities

  • Looks bloated from fluid retention

  • Frequently diets

  • Shows extreme concern with body weight and shape

  • Frequent checking in the mirror for perceived flaws in appearance

  • Has secret recurring episodes of binge eating (eating in a discrete period of time an amount of food that is much larger than most individuals would eat under similar circumstances); feels lack of control over ability to stop eating

  • Purges after a binge (e.g. self-induced vomiting, abuse of laxatives, diet pills and/or diuretics, excessive exercise, fasting)

  • Extreme mood swings


  • Noticeable fluctuations in weight, both up and down

  • Bodyweight is typically within the healthy weight range; may be overweight

  • Stomach cramps, other non-specific gastrointestinal complaints (constipation, acid reflux, etc.)

  • Difficulties concentrating

  • Abnormal laboratory findings (anemia, low thyroid and hormone levels, low potassium, low blood cell counts, slow heart rate)

  • Dizziness

  • Fainting/syncope

  • Feeling cold all the time

  • Sleep problems

  • Cuts and calluses across the top of finger joints (a result of inducing vomiting)

  • Dental problems, such as enamel erosion, cavities, and tooth sensitivity

  • Dry skin

  • Dry and brittle nails

  • Swelling around area of salivary glands

  • Fine hair on body

  • Thinning of hair on head, dry and brittle hair (lanugo)

  • Cavities, or discoloration of teeth, from vomiting

  • Muscle weakness

  • Yellow skin (in context of eating large amounts of carrots)

  • Cold, mottled hands and feet or swelling of feet

  • Menstrual irregularities — missing periods or only having a period while on hormonal contraceptives (this is not considered a "true" period)

  • Poor wound healing

  • Impaired immune functioning

Many people with bulimia nervosa also struggle with co-occurring conditions, such as:

  • Self-injury (cutting and other forms of self-harm without suicidal intention)

  • Substance abuse

  • Impulsivity (risky sexual behaviors, shoplifting, etc.)

  • Diabulimia (intentional misuse of insulin for type 1 diabetes)


For the most part, the cause of BN is unknown. Research has shown that there isn't one cause connected to every case of bulimia, but a multitude of interchangeable reasons. Not every case is the same. Causes are physiological, biological, and environmental.

Studies have shown a link between bulimia and serotonin levels. Serotonin is a chemical in the brain that affects a variety of psychological and biological factors, including hunger, anxiety, impulsivity, perception, and memory.

Mental Health Disorders. Other mental health disorders can lead to BN. Studies show that half of binge eating disorder patients have a history of depression or other mental illness. Many people report negative emotions associated with bulimia such as anxiety, boredom, anger, and sadness.

Run in Families. Families share not only genetics but also eating habits. Though more research is required, some studies have indicated that eating disorders can be passed down from generation to generation through genetic factors. Parents also pass down their eating habits to their children, so if the parents have a pattern of bulimia, the children will more likely too.

Emotional Trauma. Stress can cause BN, more specifically, stressful life events like divorce, abuse, or death. Eating disorders can be used as a coping mechanism for traumatic experiences.

Weight Problems. One characteristic of bulimia nervosa patients is the fear of gaining weight. Either could come first, BN or weight issues, but there is no dispute that the problems are related.

Body Image. People with a negative body image are more likely to develop an eating disorder. In an obesity study, individuals who were overweight and individuals with binge eating disorder reported that self-esteem related to weight and shape. A negative body image can develop if a person is influenced by media or wants to live up to societal standards or norms. An adverse body image can lead to frequent dieting and overeating.


Credit to NEDA.

Bulimia is at a higher prevalence than previously thought. One study concluded that 1.0% of young women and 0.1% of young men met the diagnostic criteria at any given time. A 2007 survey of Americans found that 1.5% of women and 0.5% of men had bulimia during their lifetime. A review paper combined several studies to deduced that 1.1% and 4.6% of women and 0.1% to 0.5% of men would develop bulimia. Though the rate of bulimia nervosa patients hasn't been nailed down, research and clinical reports agree that eating disorder symptoms develop early in both males and females.

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Hoek HW and van Hoeken D. (2003). Review of the prevalence and incidence of eating disorders. International Journal of Eating Disorders, 34(4):383-96. doi: 10.1002/eat.10222.

Hudson JI, Hiripi E, Pope HG Jr, and Kessler RC. (2007). The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication. Biological Psychiatry, 61(3):348-58. doi:10.1016/j.biopsych.2006.03.040.

Micali N, Hagberg KW, Petersen I, and Treasure JL. (2013). The incidence of eating disorders in the UK in 2000–2009: findings from the General Practice Research Database. BMJ Open, 3(5): e002646. doi: 10.1136/bmjopen-2013-002646.

Smink FR, van Hoeken D, and Hoek HW. (2012). Epidemiology of eating disorders: incidence, prevalence and mortality rates. Current Psychiatry Reports, 14(4):406-14. doi: 10.1007/ s11920-012-0282-y.

Stice E & Bohon C. (2012). Eating Disorders. In Child and Adolescent Psychopathology, 2nd Edition, Theodore Beauchaine & Stephen Linshaw, eds. New York: Wiley.

Stice E, Marti CN, Shaw H, and Jaconis M. (2010). An 8-year longitudinal study of the natural history of threshold, subthreshold, and partial eating disorders from a community sample of adolescents. Journal of Abnormal Psychology, 118(3):587-97. doi: 10.1037/a0016481.

van Son GE, van Hoeken D, Bartelds AI, van Furth EF, and Hoek HW. (2012). Time trends in the incidence of eating disorders: a primary care study in the Netherlands. International Journal of Eating Disorders, 39(7):565-9. doi: 10.1002/eat.20316.

Health Consequences

Cardiovascular System

  • When you don't consume enough calories, the body breaks down its tissue for fuel instead. The first tissue to be used is a muscle, including the heart. The more mass the heart loses, the more pulse and blood pressure drop. The heart has less fuel and cells to pump blood, and the risk of heart failure increases.

  • The body will reduce its resting metabolic rate to conserve energy.

  • If the brain and blood vessels can't push enough blood to the brain, it can cause fainting or dizziness, primarily upon standing.

  • Vomiting or laxatives can deplete body electrolytes. Electrolytes are used to help the heartbeat and other neurological activities. Imbalances in these chemicals can lead to irregular heartbeats, heart failure, and possibly death.