Anorexia Nervosa (Medical Complications)MANAGEMENT

PSYCHIATRIC PRESENTATIONS · 12 SECTIONS

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469 items

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Acute anxiety Acute psychosis Agitation-behavioral emergency Anorexia Nervosa (Medical Complications)Bipolar disorder Bipolar Disorder (Depressive Episode)Bipolar Disorder (Manic Episode)Bulimia Nervosa (Medical Complications)Catatonia Conversion disorder Dementia and behavioral crisis Factitious Disorder Failure to Cope (Social)Failure to Thrive Generalized Anxiety Disorder Homicidal Ideation Major Depressive Disorder Major depressive episode Malingering Neuroleptic malignant syndrome Panic Attack Post-Traumatic Stress Disorder (Acute)Schizophrenia Exacerbation Suicidal Ideation Suicidal ideation and attempt Suicide Attempt

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

01Approach to the Critical Patient/attcp55

Immediate priorities

›Life-threatening derangements of starvation

›Hemodynamic instability

›HR < 50 bpm daytime or < 45 bpm at night

›BP < 90/45 mmHg

›Orthostatic pulse rise > 20 bpm or SBP drop > 20 mmHg

›Cardiac arrhythmia risk

›QTc > 440 ms with torsades risk

›Hypokalemia and hypomagnesemia potentiating arrhythmia

›Severe metabolic derangement

›Hypophosphatemia

›Hypoglycemia

›Hyponatremia

›Hypothermia < 35.6 C

›Passive rewarming with warm blankets

›Core temperature monitoring

›Refeeding syndrome vigilance

›Highest risk in first 72 hours of nutritional rehabilitation

›Precipitous phosphate drop

›Tachycardia, tachypnea, edema

›Thiamine 100 mg IV before any dextrose or feeding

›Prevents Wernicke encephalopathy

›Continue 5 to 7 days

›If cardiac or respiratory decompensation, slow caloric advancement

›Aggressive electrolyte repletion

›Continuous cardiac monitoring

Monitoring and targets

›Monitoring bundle

02History/hx51

Eating disorder behaviors

›Restriction pattern

›Duration and severity of caloric restriction

›Specific foods avoided

›Rules and rituals about eating

›Weight trajectory

›Rate of loss

›Lowest and premorbid weight

›Body checking behaviors

›Frequent weighing

›Mirror checking and measuring

›Purging and compensatory behaviors

›Self-induced vomiting

›Frequency and duration

›Hematemesis from Mallory-Weiss tear

›Laxative, diuretic, or enema misuse

›Laxative dependence

›Diet pill or stimulant use

›Compulsive exercise

›Exercising despite injury or illness

›Binge episodes with loss of control

Associated symptoms and comorbidity

›Constitutional and endocrine clues

›Oligomenorrhea or amenorrhea present in ~78% of females

›Duration of amenorrhea

›Reproductive history

›Cold intolerance and fatigue

›Hair loss

03Physical Exam/exam34

Vital signs

›Hemodynamic findings

›Bradycardia

›Sinus, may worsen during sleep

›HR < 50 bpm daytime concerning

›Hypotension

›Orthostatic changes prominent

›BP < 90/45 mmHg

›Hypothermia

›Core temperature < 35.6 C

›Poor peripheral perfusion

General and integumentary

›Nutritional and skin signs

›Cachexia

›Temporal wasting

›Prominent bony landmarks

›Lanugo

›Fine downy hair on face, neck, arms

›Dry, scaly skin

›Peripheral edema

›Hypoalbuminemia

›Refeeding-associated fluid shift

Targeted systems

›Cardiovascular exam

›Bradycardia and irregular rhythm

›Acrocyanosis

›Mitral valve prolapse murmur from decreased LV mass

›Purging-specific signs

04Differential Diagnosis/ddx40

Cannot-miss organic mimics

›Endocrine and oncologic

›Hyperthyroidism

›Weight loss with tachycardia and tremor

›Opposite vital sign pattern to AN

›Addison disease

›Hypotension and hyperpigmentation

›Electrolyte abnormalities

›Malignancy

›Lymphoma or GI cancer

›Night sweats and lymphadenopathy

›Metabolic and structural

›Type 1 diabetes

›Polyuria and polydipsia

›Weight loss with hyperglycemia

›CNS lesion

›Hypothalamic or pituitary tumor

›Endocrine dysfunction

Gastrointestinal and eating disorder spectrum

›GI mimics

›Inflammatory bowel disease

›Abdominal pain and diarrhea

›Growth failure

›Celiac disease

›Malabsorption

›May coexist with AN

›Superior mesenteric artery syndrome

›Both complication and mimic

05Laboratory Tests/lt42

Core metabolic and hematologic panel

›Hematologic studies

›Complete blood count

›Leukopenia with relative lymphocytosis

›Mild anemia and thrombocytopenia

›Inflammatory markers

›Depressed ESR

›Low-grade marrow suppression

›Electrolytes and renal

›Basic metabolic panel

›Hypokalemia and hyponatremia

›Metabolic alkalosis from vomiting

›Metabolic acidosis from laxative abuse

›Renal function

›Elevated BUN from dehydration

›Declining GFR over time

Refeeding-critical electrolytes

›Phosphate, magnesium, glucose

›Phosphorus

›Decreased and critical to monitor during refeeding

›Repeat every 12 hours first 72 hours in high-risk patients

›Magnesium

›Decreased

›Repletion before refeeding

›Glucose

›Hypoglycemia

›Bedside point-of-care testing

06Diagnostic Tests/dt53

Scoring Systems

›Screening and severity tools

›SCOFF questionnaire

›Sick, Control, One stone, Fat, Food

›2 or more positive responses prompts evaluation

›DSM-5 severity by adult BMI

›Mild BMI >= 17

›Moderate BMI 16 to 16.99

›Severe BMI 15 to 15.99

›Extreme BMI < 15

›Adolescent stratification

›Percent median BMI for age and sex

›BMI <= 75% median is high risk

›Limitations

›Normal labs do not exclude serious illness

›Results often normal early in disease

›Clinical trajectory supersedes single score

›Scores do not capture refeeding risk

›Severity changes rapidly

›Serial reassessment required

MRI

›Brain MRI role

›Indications

›Focal neurologic deficits

›Diagnostic uncertainty for CNS mass

›Expected findings

›Sulcal widening and ventricular dilatation

›Cerebral pseudoatrophy largely reversible with weight restoration

07Disposition/dispo33

Admission criteria

›Medical instability triggers

›Vital sign thresholds

›HR < 50 daytime or < 45 nighttime

›BP < 90/45 mmHg

›Hypothermia < 35.6 C

›Severe malnutrition

›BMI <= 15 in adults

›BMI <= 75% median for adolescents

›Electrocardiographic abnormality

›Prolonged QTc

›Arrhythmia

›Other admission indications

›Electrolyte disturbance

›Hypokalemia, hyponatremia, hypophosphatemia

›Acute complication such as syncope or seizure

›Behavioral and psychiatric

›Acute food refusal

›Suicidal ideation or psychiatric emergency

›Failure of outpatient treatment

Discharge and consultation

›Discharge criteria

›Medical stability

›Stable vital signs with resolving orthostasis

›Electrolytes normalizing and tolerating oral intake

›Psychiatric safety

›No active suicidal ideation

›Outpatient multidisciplinary team in place

08Treatment/t50

Initial stabilization

›Resuscitation measures

›Access and monitoring

›IV access and cardiac monitoring

›Orthostatic vital signs

›Cautious volume correction

›Avoid rapid fluid boluses in severe malnutrition

›Monitor for edema during rehydration

›Correct acute derangements

›Treat hypoglycemia

›Warm blankets for hypothermia

Electrolyte repletion

›Prophylactic and corrective repletion

›Potassium

›2 to 4 mmol/kg/day during refeeding

›Continuous monitoring if hypokalemic

›Phosphate

›0.3 to 0.6 mmol/kg/day

›IV repletion if precipitous drop

›Magnesium

›0.2 to 0.4 mmol/kg/day

›Repletion before potassium correction if both low

Refeeding protocol

›Structured nutritional rehabilitation

›Thiamine prophylaxis

›100 mg IV or PO before any dextrose or feeding

›Multivitamin daily for at least 10 days

›Caloric prescription

09Special Populations/sp39

Pregnancy

›Pregnancy considerations

›Maternal and fetal risk

›Intrauterine growth restriction

›Higher miscarriage and preterm birth risk

›Nutritional management

›Increased caloric and micronutrient needs

›Folate and iron supplementation

›Monitoring approach

›Serial growth ultrasound

›Coordinated obstetric and psychiatric care

›Medication safety

›Avoid teratogenic agents

›Reassess psychotropics for pregnancy safety

Geriatric

›Older adult features

›Atypical presentation

›Late-onset or relapsing disease

›Overlap with organic causes of weight loss

›Higher complication burden

›Greater fracture risk from baseline osteoporosis

›Reduced physiologic reserve for refeeding

›Pharmacologic caution

›Renal dosing adjustment

›Higher QT prolongation risk

›Disposition bias

›Lower threshold for admission

›Limited home supports

10Background/b37

Epidemiology

›Burden and mortality

›Highest mortality of any psychiatric disorder

›5 to 6 fold increased mortality versus age-matched controls

›About one-third of deaths from cardiovascular complications

›Demographic distribution

›Peak onset in adolescence and young adulthood

›Female predominance with rising male recognition

›Chronicity and relapse

›High relapse rate

›About 40% of hospitalized youth require readmission

Pathophysiology

›Mechanisms of complication

›Hypometabolic starvation state

›Every organ system affected

›Cumulative complications over time

›Refeeding syndrome mechanism

›Insulin-mediated intracellular shift of phosphate, potassium, magnesium

›Triggered by carbohydrate reintroduction after starvation

›Cardiovascular adaptation

›Decreased LV mass with functional MVP

›QTc prolongation with arrhythmia risk

›Endocrine and skeletal

›Hypogonadotropic hypogonadism with amenorrhea

›Osteopenia in about 1 in 3 patients

Therapeutic Considerations

›Treatment principles

›Nutrition as primary therapy

11Patient Discharge Instructions/pdi22

copy discharge instructions

›Anorexia nervosa home care

›Follow the meal plan from your dietitian

›Take prescribed vitamins and electrolyte supplements

›Keep all medical, therapy, and dietitian appointments

›Do not skip meals or restart restriction or purging

›Warning signs to return to ER

›Dizziness, fainting, or near-fainting

›Chest pain, palpitations, or irregular heartbeat

›Severe weakness or inability to stand

›Confusion or seizures

›Inability to keep food or fluids down

›Worsening depression or thoughts of self-harm

›Swelling of legs or rapid weight gain

›Severe abdominal pain or bloating

›Follow up

›Weekly medical and laboratory monitoring during weight restoration

›Weekly therapy sessions

›Blood tests for electrolytes at each early visit

›Recovery expectations

›Most starvation effects improve with weight gain

›Bone density may need long-term monitoring

›Relapse is common, so stay connected to your care team

12References/r13

Guidelines and key sources

›Guideline sources

›American Psychiatric Association eating disorder guidelines

›Society for Adolescent Health and Medicine admission criteria

›American Academy of Pediatrics eating disorder guidance

›Landmark reviews and trials

›Trapani and Rubino, Medical Complications of Anorexia Nervosa, Pediatrics 2025

›Treasure, Duarte, Schmidt, Eating Disorders, Lancet 2020

›Mitchell and Peterson, Anorexia Nervosa, NEJM 2020

›ASPEN Consensus Recommendations for Refeeding Syndrome 2020

›Coding standards

›ICD-10 F50.0 anorexia nervosa

›ICD-10 F50.00 restricting type and F50.01 binge-eating/purging type

›SNOMED CT anorexia nervosa disorder concept

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Reviewed by SymptomDx Medical Team · Last reviewed August 18, 2026

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