Eating Disorders: Comprehensive Assessment, Medical Management and Nursing Care
Eating disorders are serious mental and behavioural disorders involving persistent disturbances in eating, weight-control behaviour or body-image experience that impair physical health or psychosocial functioning. They occur at any body size, sex, age or social group. A person who appears well or has a “normal” body mass index may still be medically unstable.
Emergency warning: syncope, chest pain, severe weakness, confusion, seizures, dehydration, haematemesis, marked bradycardia/hypotension, hypothermia, electrolyte disturbance, uncontrolled vomiting, acute food refusal or high suicide risk requires urgent medical assessment. Refeeding can itself cause fatal electrolyte and cardiac complications.
Classification
| Disorder | Core clinical pattern | Important clarification |
|---|---|---|
| Anorexia nervosa | Significantly low weight for the individual, persistent restrictive behaviour or other actions preventing weight restoration, and overvaluation/fear related to weight or shape. | May be restricting or binge–purge pattern; severity is not judged by appearance alone. |
| Bulimia nervosa | Recurrent binge eating with loss of control followed by compensatory vomiting, fasting, excessive exercise or misuse of laxatives/medicines. | Weight may be within or above the expected range. |
| Binge-eating disorder | Recurrent distressing binges without regular compensatory behaviour. | Not simply “overeating”; assess shame, depression and metabolic health. |
| ARFID | Avoidant/restrictive intake due to sensory sensitivity, fear of consequences or low interest, causing nutritional/functional impairment. | Not driven by weight/shape concerns. |
| Pica/rumination | Persistent non-food ingestion or repeated regurgitation/rechewing. | Exclude cultural practice, developmental and medical causes. |
Aetiology and maintaining mechanisms
- Biological vulnerability: genetic susceptibility, temperament, puberty, appetite/reward pathways and coexisting anxiety, depression, OCD traits or neurodevelopmental conditions.
- Psychological: perfectionism, low self-worth, emotion-regulation difficulty, trauma and rigid thinking may make control of eating feel temporarily protective.
- Social/cultural: weight stigma, bullying, appearance pressure, sport/occupation demands, food insecurity and family stress influence risk but are not single causes.
- Starvation cycle: restriction produces preoccupation, cognitive rigidity, low mood, gastrointestinal slowing and reduced appetite, which then reinforce further restriction.
- Binge–purge cycle: dietary restraint and distress precipitate bingeing; compensatory behaviour briefly reduces fear but strengthens the cycle and causes medical harm.
Clinical manifestations
History clues
- Skipping meals, rigid food rules, secret eating, disappearing after meals, vomiting, laxative/diuretic misuse, excessive exercise or rapid dietary change.
- Preoccupation with calories, weight or shape; fear of weight gain; body checking; shame and social avoidance.
- Dizziness, fainting, weakness, cold intolerance, constipation, abdominal bloating, menstrual/reproductive changes, dental sensitivity and sleep disturbance.
Physical findings and complications
- Cardiovascular: bradycardia, hypotension, orthostatic change, arrhythmia and cardiomyopathy from malnutrition/electrolyte loss.
- Metabolic: hypoglycaemia, hypokalaemia, hypomagnesaemia, hypophosphataemia, dehydration and renal injury.
- Gastrointestinal/dental: delayed gastric emptying, constipation, reflux, oesophageal tears, parotid enlargement and enamel erosion.
- Endocrine/bone: hypogonadism, reduced fertility, impaired growth and low bone density.
- Neuropsychiatric: cognitive slowing, irritability, depression, self-harm and elevated suicide risk.
Comprehensive assessment
- Engage without blame: interview privately, explain confidentiality, avoid praising weight loss or debating appearance.
- Eating behaviour: usual intake, restriction, binge frequency, compensatory methods, exercise, fluids, supplements/herbal products and recent change.
- Medical and reproductive: syncope, palpitations, vomiting/blood, bowel function, diabetes, pregnancy, menstrual history and all medicines.
- Mental health: depression, anxiety, OCD, trauma, substances, self-harm, suicide, abuse and safeguarding.
- Examination: weight trend and growth where relevant, temperature, pulse, lying/standing BP, hydration, cardiac examination, muscle strength, oral/dental and signs of purging. Measurements must be respectful and clinically purposeful.
Investigations
Use clinical severity to guide FBC, glucose, urea/creatinine, electrolytes including potassium, phosphate and magnesium, calcium, liver tests, urinalysis, pregnancy testing and ECG. Consider thyroid/coeliac and other tests only when indicated. Normal laboratory results do not prove safety: trends, observations, intake and ECG matter.
Management
Admission and stabilization
- Admit or urgently refer for physiological instability, serious electrolyte/ECG abnormality, uncontrolled purging, severe dehydration, acute food refusal, rapid deterioration, high suicide risk or inadequate safe support.
- Correct immediately dangerous glucose, fluid and electrolyte problems cautiously with cardiac monitoring; avoid rapid uncontrolled fluid replacement.
- Assess refeeding risk before nutrition. Start an individualized dietitian/medical plan, give thiamine and replace electrolytes according to protocol, and monitor phosphate, potassium, magnesium, glucose, fluid balance, oedema, cardiac and respiratory status.
Nutritional rehabilitation
- Set collaborative meal and weight-restoration goals; provide supervised meals and time-limited post-meal support when purging risk is high.
- Oral nutrition is preferred when possible. Nasogastric feeding is a medical treatment for defined indications, not punishment; explain consent/legal basis, monitoring and review.
- Avoid bargaining, shaming or coercive comments. Separate the person’s identity from illness-driven behaviour.
Psychological and family treatment
- Eating-disorder-focused CBT supports regular eating, reduces restraint/compensatory behaviour and addresses overvaluation of shape/weight.
- Family-based treatment is important for many children/adolescents and supports caregivers to restore nutrition without blame.
- Treat trauma, depression, anxiety and substance use in coordinated sequence; starvation can reduce psychotherapy concentration.
Medicines
| Medicine issue | Role | Contraindications/adverse effects/monitoring |
|---|---|---|
| Antidepressants | May help bulimia/binge-eating symptoms and comorbid depression; not a substitute for nutritional/psychological treatment. | Check QT/electrolytes, activation and suicide risk. Response in severely undernourished anorexia may be limited. |
| Bupropion | Not used in bulimia/anorexia. | Contraindicated because seizure risk is increased. |
| Antipsychotics | Selected severe rigidity/anxiety under specialist care; not routine weight-gain agents. | Metabolic, cardiac, EPS and sedation monitoring. |
| Laxatives/diuretics | Do not reduce absorbed calories/body fat. | Misuse causes dehydration, renal injury and electrolyte disturbance; supervised withdrawal may be required. |
Detailed nursing care plan
| No. | Intervention | Rationale and measurable outcome |
|---|---|---|
| 1 | Monitor pulse, BP/orthostasis, temperature, ECG risk, glucose, electrolytes, fluid balance and deterioration symptoms at prescribed intervals. | Detects arrhythmia, shock, hypoglycaemia and refeeding syndrome. Outcome: stable observations and correcting laboratory trends. |
| 2 | Use an agreed meal plan; provide calm supervision and record intake without criticism. | Supports nutritional restoration and reduces concealment. Outcome: prescribed intake completed with falling distress over time. |
| 3 | Maintain post-meal observation when indicated; restrict bathroom access only within a transparent, reviewed therapeutic plan. | Interrupts purging while respecting dignity. Outcome: reduced compensatory episodes. |
| 4 | Assess suicide/self-harm and excessive-exercise urges repeatedly; match observation to dynamic risk. | Risk may rise with shame, depression or early recovery. |
| 5 | Use consistent team language and boundaries; avoid weight/appearance comments. | Prevents splitting, stigma and reinforcement of illness beliefs. |
| 6 | Teach patient/family refeeding symptoms, medicine risks, relapse signs and follow-up. | Improves early recognition and continuity after discharge. |
Discharge and relapse prevention
- Discharge only with stable physiology, feasible nutrition plan, suicide/safeguarding plan, responsible follow-up and clear return signs.
- Relapse signs include renewed restriction, secrecy, meal avoidance, increasing exercise, body checking, purging or falling function—not weight alone.
- Coordinate mental health, medical, dietetic, dental, reproductive and family care.
Revision questions
- Differentiate anorexia nervosa, bulimia nervosa, binge-eating disorder and ARFID.
- Explain refeeding syndrome and its monitoring.
- Develop six nursing diagnoses with measurable outcomes.
- Why may apparently normal weight/laboratory results be falsely reassuring?
References
- WHO. ICD-11 Clinical Descriptions and Diagnostic Requirements, 2024.
- WHO. mhGAP Guideline, 2023.
- NICE. Eating Disorders: Recognition and Treatment, updated guidance.