Synopsis
Confirm clinically important weight loss, identify malignancy, dysphagia, inflammatory disease, endocrine illness, mental ill health and deprivation without diagnostic anchoring, and start safe nutrition support with explicit refeeding-risk management.
- Verify measured weights, timeframe, percentage change and fluid shifts; a patient's concern matters even when the available chart is incomplete.
- Malnutrition is not synonymous with low BMI: oedema and obesity can conceal major muscle loss, while ascites can make weight appear stable.
- Separate reduced intake, impaired absorption, increased requirements or losses, and catabolic disease; more than one mechanism commonly coexists.
- Dysphagia, gastrointestinal bleeding, jaundice, a mass, persistent vomiting, progressive pain or site-specific cancer features require the current urgent referral pathway.
- Screen with a validated tool and assess function, muscle, dentition, swallowing, food access, mood, alcohol and medication effects rather than ordering tests alone.
- People who have eaten little or nothing for more than five days need cautious introduction of support; those at high refeeding risk need specialist feeding, thiamine and electrolyte planning.
- Use the gut when it is functional and safe: oral optimisation first where possible, enteral feeding when intake is inadequate or unsafe, and parenteral support when the gastrointestinal route is inadequate or inaccessible.
- Nutrition support requires consent, shared goals and review; capacity, eating disorders, neglect and food insecurity need sensitive specialist or safeguarding involvement.
Key red flags
Progressive dysphagia, iron-deficiency anaemia, rectal bleeding, jaundice, palpable mass, persistent vomiting, focal pain or new change in bowel habit with weight loss requires the live NICE suspected-cancer pathway.
Very low BMI, rapid loss, visible muscle wasting, weakness, pressure damage, recurrent falls, poor wound healing, oedema or inability to maintain intake indicates high physiological risk even if routine blood tests are normal.
Little or no intake, very low BMI, major recent weight loss, low phosphate, potassium or magnesium, harmful alcohol use, or medicines such as insulin, chemotherapy, antacids or diuretics can place a patient at high risk.
Coughing with meals, wet voice, recurrent chest infections, food sticking, odynophagia or neurological disease requires distinction between oropharyngeal and oesophageal dysphagia and prompt speech-and-language or endoscopic assessment.
Investigation priorities
Record current and previous weights, height, BMI, percentage loss, intake history, MUST or another validated score, grip or functional change, muscle and fat loss, oedema and hydration.
Management branches
Objective or credible weight loss accompanies a cancer, obstruction, infection or organ-failure warning sign.
- Assess urgency, hydration, sepsis, bleeding, aspiration and electrolyte disturbance; admit or escalate on the same day when unstable or unable to maintain intake.
- Use the current NICE symptom- and age-specific suspected-cancer recommendation rather than relying on a remembered threshold.
- Start proportionate nutrition and symptom support while investigation proceeds, with dietetic and swallowing input where relevant.
- Create a result and referral owner so an urgent diagnostic pathway does not leave malnutrition untreated.