Decreased appetite
🍽️ Decreased appetite (anorexia) = reduced desire to eat.
It is a non-specific symptom seen in many physical, psychological, and social conditions.
Recognising red flags (weight loss, systemic illness, malignancy) is key in clinical practice.
🩺 Clinical Features
- ⚖️ Weight loss: Unintentional, may indicate malnutrition or malignancy.
- 😴 Fatigue: Reduced energy due to poor caloric intake.
- 🧩 Associated symptoms:
- Abdominal pain, nausea, vomiting → GI disorders
- Fever → infection
- Low mood, anhedonia → psychological cause
🔍 Diagnostic Approach
- 🗣️ History: Onset, duration, associated GI or systemic symptoms, recent illness, medications.
- 👀 Physical exam: Signs of malnutrition, abdominal tenderness, neurological deficits.
- 🧪 Laboratory tests:
- FBC (anaemia, infection)
- U&E, Ca²⁺, Mg²⁺, Phosphate
- LFTs, TFTs, coeliac screen
- Glucose, HbA1c
- 🖼️ Imaging:
- Abdominal USS/CT → malignancy, IBD
- CXR → TB, lung tumour, fibrosis
- 🧠 Psychological assessment: Screen for depression, anxiety, eating disorders.
🧪 Common Causes of Decreased Appetite (Anorexia)
- Gastrointestinal (GI) Disorders
- Gastritis, peptic ulcer disease (PUD)
- Gastro-oesophageal reflux disease (GORD)
- Inflammatory bowel disease (Crohn’s, ulcerative colitis)
- Gastroenteritis (viral, bacterial, parasitic)
- GI malignancy (stomach, pancreas, colon, liver)
- Infections
- Acute: influenza, pneumonia, urinary tract infection
- Chronic: tuberculosis, HIV, hepatitis, endocarditis
- Psychological & Psychiatric
- Depression 😔
- Anxiety 😰
- Eating disorders (anorexia nervosa, bulimia)
- Stress, bereavement, social isolation
- Medications 💊
- Chemotherapy drugs
- Opioids
- Antibiotics (e.g., metronidazole, macrolides)
- Metformin
- Digoxin
- SSRIs and antipsychotics
- Endocrine & Metabolic
- Hypothyroidism
- Diabetes mellitus (esp. uncontrolled or DKA)
- Adrenal insufficiency (Addison’s disease)
- Hypercalcaemia
- Chronic kidney disease (uraemia)
- Chronic liver disease (cirrhosis, hepatitis)
- Malignancy 🧬
- Cancer cachexia (due to cytokine release)
- Common: gastric, pancreatic, lung, lymphoma
- Neurological
- Dementia
- Parkinson’s disease
- Stroke (esp. brainstem)
- Raised intracranial pressure (tumour, bleed, infection)
- Other Systemic Causes
- Chronic heart failure
- COPD with hypoxia
- Post-surgery / prolonged hospital admission
- Old age / frailty
🛠️ Management Principles
- 🎯 Treat underlying cause: infections, endocrine disease, GI disorders.
- 🥗 Nutritional support: Supplements, dietitian referral, enteral/parenteral feeding if needed.
- 💊 Appetite stimulants: Consider mirtazapine, megestrol, or steroids (esp. in palliative settings).
- 🧠 Psychological support: CBT, counselling, psychiatry referral.
- 💊 Medication review: Identify and adjust drugs causing anorexia.
📈 Prognosis
Prognosis depends on cause.
✅ Short-term anorexia from infection often resolves with treatment.
⚠️ Chronic causes (e.g., cancer, CKD, dementia) require long-term supportive care and may carry poor prognosis if untreated.
Early recognition + targeted management can prevent malnutrition and improve outcomes.
