The pathobiology of anorexia and bulimia nervosa

1. Anorexia & Bulimia
By Joe Yang
and Narattapat Watcharapariyapat

2. Bulimia and Anorexia: The Similarity
• Both types are classified as eating disorders.
• The actual or specific causes (etiology) and pathogenesis
of both types are currently unclear.
• Both are considered progressive diseases; that is they
get worse and worse as time progresses.
• Both types affect women more than men worldwide.
• Both types are considered incurable diseases; only
treatments and remission (temporary end) are possible.

3. Bulimia and Anorexia: The Difference
• Different signs and symptoms
• Different criteria of diagnosis
• Different threats to health problems
• Different courses of treatments
• Different prevalence rates

4. Intro of anorexia
• It is a disorder where victims mentally believes that they are
overweigh, regardless of their true weight.
• People who are anorexic, their minds are not their own, they
felt unattractive and ugly but still want to be thin (Toby D.
Goldsmith, 2013)

5. Etiology of anorexia
• One main factor; through cultural & peer pressure in pursuit
of perfect or attractive body shape (The Canadian Journal of
Psychiatry, 1981)
• Sudden change in diet, causing stress onto the body, thus
develop anorexia. Though may be caused by genetic heritage,
abnormal neurotransmissions, along with combinations of
personality traits.
• Thought to be a skill applied when coping with stress (
WebMD, 2013)

6. Pathogenesis of anorexia
• Anorexia develops as the victims ingest less foods,
eventually lack of nutrients, leading to the full developments
of anorexia.
• Patients suffer from constipation, muscle weakness due to
lack of nutrients and waking up unusually early, caused by
the hormone disturbance (Newbridge, N/A)

7. Pathogenesis of anorexia
• Most crucially, anorexia causes atrophy of many organs within
the body, such as the heart, leads to problems such as
hypovolemia, victim have lack of oxygen.
• Victims would also have arrhythmia, for the victim have lack of
energy to maintain regular heartbeat (Cardiol Rev, 2006)

8. Diagnosis of anorexia
• When diagnosing anorexia, be aware of how people answer
questions concerning weight.
• Check for weight and BMI
• Check for irregular heartbeat, blood tests

9. Treatment for anorexia
nervosa
• From Douglas Rhein , the most common treatment for
anorexia is cognitive behavioral therapy, although the
treatment is not as effective as those when compared with
the effects having when treating anxiety and mild depression.
• Strictly speaking, there are no effective treatment for
anorexia.

10. Bulimia Nervosa
© 2011 - 2012 Doctor Tipster

11. Bulimia Nervosa: The Definition
Bulimia nervosa is characterized by “recurrent and frequent episodes of
eating unusually large amounts of food and feeling a lack of control over
these episodes. This binge-eating is followed by behavior that compensates
for the overeating such as forced vomiting, excessive use of laxatives or
diuretics, fasting, excessive exercise, or a combination of these behaviors”
(NIMH, 2011).
Feeling ashamed
Strict Dieting
Binge eating
(Overeating)
Removal of Food
(purging, etc.)
*Purging =
self-induced
vomiting, uses of
laxatives, diuretics
and/or enema

12. DIY Enema Kit
The enema kit that can be found in Constipation Remedies by Dr. Stephen.
most store, by PatBlockNY An enema washes out the rectum and
lower colon by PatBlockNY.

13. Etiology of Bulimia Nervosa
• The exact cause of bulimia is unknown (A.D.A.M, 2012).
• Physiologically, it may be caused by an abnormality of serotonergic
(serotonin-related) neuron functioning (Micah Orliss, N/A)
• Some evidence supports that it may be a genetic disease (Micah Orliss,
N/A).
• Stress caused by dieting may lead to binge eating, which then leads to
purging (Micah Orliss, N/A).
• In sociocultural viewpoint, bulimia is cause by the “ideal thin” body vastly
portrayed in the media (Micah Orliss, N/A).

14. Pathogenesis of Bulimia Nervosa
• The exact pathogenesis is unclear (Brambilla, 2001).
• Generally, “people may binge and purge when they have low self-esteem,
when they are pressured to conform to eating or to adhere to a
specific weight and shape, and when they are knowledgeable about
bingeing and purging. Compensatory behaviors such as vomiting, use of
laxatives, or exercise may result in large fluctuations in weight that
reinforce the behavior” (British Medical Journal, 2012).
• One hypothesis suggests that if serotonergic neurons were inadequate or
ineffective it could cause an enhanced craving for food rich in
carbohydrates (Micah Orliss, N/A).

15. Signs & Symptoms of Bulimia Nervosa
Purging Type
• Dental and enamel erosion
• Swollen salivary glands (sialosis/sialadenosis)
• Callused and/or discolored skin on the finger joints (Russell's sign)
• Tooth decalcification
• Irregularly-shaped biting edges of teeth
• Increase in number of cavities
• Swollen cheeks and jaw
• Bloodshot eyes
• Metabolic acidosis, metabolic alkalosis
• Hypochloremia, hypokalemia, hyperamylasemia, hyperchloesterolimia
(ECRI Institute, 2013)

16. Dental and enamel erosion
Source: Figure 1. Pretreatment dentition. A, Frontal view. B, Right side. C, Left side. D, Maxillary view. E, Mandibular view by
Stefanie Schwarz, Alexander Kreuter, and Peter Rammelsberg; Efficient prosthodontic treatment in a young patient with long-standing
bulimia nervosa: A clinical report

17. Sialosis/Sialadenosis
External feature of sialosis
Microscopy showing acinar hypertrophy with
granular cytoplasm and compression of the
striated ducts
Source: British Journal of Oral and Maxillofacial Surgery, Sialosis: 35
cases of persistent parotid swelling from two countries by Crispian
Scully, Jose V. Bagán, et al.

18. Russell's sign
©2013 Eating Disorders Advice, Russell’s sign – callussed
knuckles from repeatedly inducing vomiting

19. Signs & Symptoms of Bulimia Nervosa
Non-purging Type
• Excessive exercise
• Abusive uses of over-the-counter diet pills
• Engagement of extended period of fasting
• (No signs of vomiting , and no use of laxatives and enema)
(ECRI Institute, 2013)

20. Diagnostic Criteria for Bulimia Nervosa
The Diagnostic and Statistical Manual of Mental Disorders (DSM)
by American Psychiatric Association
• A. Recurrent episodes of binge eating.
• B. Recurrent inappropriate compensatory behavior in order to prevent weight gain,
such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other
medications; fasting or excessive exercise.
• C. The binge eating and inappropriate compensatory behaviors both occur, on
average, at least twice a week for three months.
• D. Self-evaluation is unduly influenced by body shape and weight.
• E. The disturbance does not occur exclusively during episodes of anorexia nervosa.
(Beth McGilley, Tamara Pryor, 1998)

21. Treatments of Bulimia Nervosa
• Cognitive behavioral therapy (CBT) (Ken Duckworth, 2012)
• Prescription medication; SSRIs (e.g. Prozac) (Ken Duckworth, 2012)
• Nutritional counseling (Havard Health, 2009)
• Interpersonal therapy (Havard Health, 2009)

22. References
• Cardiol Rev (2006). Cardiovascular complications of eating disorders. Retrieved
at:http://www.ncbi.nlm.nih.gov/ pubmed/16924163
• Newbridge (N/A). The physical effects of anorexia. Retrieved at:http://www.newbridge-health.
org.uk/factsheets/the_physical_effects_of_anorexia.php
• Toby.D (2013). An introduction to anorexia nervosa. Retrieved
at:http://psychcentral.com/lib/2006/an-introduction-to-anorexia-nervosa/
• WebMD (2013). Anorexia nervosa-cause. Retrieved at:http://www.webmd.com/mental-health/
anorexia-nervosa/anorexia-nervosa-cause
• NIMH (2011). A detailed booklet that describes the symptoms, causes, and treatments of eating
disorders. Retrieved at http://www.nimh.nih.gov/health/publications/eating-disorders/complete-index.
shtml
• A.D.A.M (2012). Bulimia. Retrieved at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001381/
• Micah Orliss (N/A). Bulimia Nervosa. Retrieved at
http://www.education.ucsb.edu/jimerson/bulimia.html#bulimia etiology
• Brambilla (2001). Aetiopathogenesis and pathophysiology of bulimia nervosa: biological bases and
implications for treatment. Retrieved at http://www.ncbi.nlm.nih.gov/pubmed/11460890
• British Medical Journal (2012). Bulimia nervosa. Retrieved at http://bestpractice.bmj.com/best-practice/
monograph/441/basics/pathophysiology.html
• ECRI Institute (2013). What are the signs and symptoms of bulimia nervosa?. Retrieved at
http://www.bulimiaguide.org/summary/detail.aspx?doc_id=9454
• Beth McGilley, Tamara Pryor (1998). Assessment and Treatment of Bulimia Nervosa. Retrieved at
http://www.aafp.org/afp/1998/0601/p2743.html#afp19980601p2743-t1
• Ken Duckworth (2012). Bulimia Nervosa. Retrieved at
http://www.nami.org/Template.cfm?Section=By_Illness&Template=/ContentManagement/ContentDi
splay.cfm&ContentID=149448
• Havard Health (2009). Treating bulimia nervosa. Retrieved at
http://www.health.harvard.edu/fhg/updates/treating-bulimia-nervosa.shtml