Evaluate Body Mass Index (BMI in kg/m²) against clinical DSM-5 Anorexia Nervosa severity stages and World Health Organization (WHO) underweight criteria. Calculate healthy weight targets with direct access to supportive crisis resources.
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Meets DSM-5 Severe Anorexia Nervosa criteria. Associated with severe lean muscle catabolism, severe bradycardia (resting heart rate < 40 bpm), postural hypotension, and severe bone mineral density loss.
Non-Diagnostic Screening Notice: This calculation is an anthropometric indicator, not a psychiatric diagnosis. A clinical diagnosis of anorexia nervosa requires an in-depth evaluation of dietary behaviors, body image perception, vital signs, and laboratory panels by a physician.
| DSM-5 Staging | BMI Cutoff | Clinical Severity & Risk |
|---|---|---|
Normal / Healthy Weight | ≥ 18.5 kg/m² | Outside diagnostic underweight criteria. Healthy physiological range. |
Mild Severity / Underweight | 17.0 – 18.49 kg/m² | Clinical screening concern (< 17.5 threshold). Early nutritional deficiency marker. |
Moderate Severity | 16.0 – 16.99 kg/m² | Significant physiological risk. Progressive hormonal, cardiac, and metabolic changes. |
Severe Severity | 15.0 – 15.99 kg/m² | High risk of severe medical complications, profound bradycardia, and electrolyte shifts. |
Extreme Severity | < 15.0 kg/m² | Critical medical emergency. BMI < 13.5 poses acute risk of organ failure and cardiac arrest. |
Anorexia nervosa is a complex biopsychosocial disorder characterized by restrictive eating, intense fear of weight gain, and body image disturbance. Below is an exhaustive clinical reference detailing diagnostic criteria, medical complications, and evidence-based care.
According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5), a formal diagnosis of Anorexia Nervosa requires meeting three mandatory criteria:
Restriction of energy intake: Persistent restriction relative to physiological requirements, leading to significantly low body weight in the context of age, sex, developmental trajectory, and physical health.
Intense fear of weight gain: Persistent fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.
Distorted body perception: Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body shape on self-evaluation, or denial of the seriousness of low body weight.
Clinical insights regarding DSM-5 criteria, atypical presentations, and recovery milestones.