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Printed on 7/20/2026
For informational purposes only. This is not medical advice.
The Malnutrition Universal Screening Tool (MUST) is a widely used adult nutrition screening framework that assigns points from three domains: BMI, unplanned weight loss, and acute disease with likely poor intake. The total score stratifies risk as low, medium, or high, helping trigger timely nutrition intervention.
Formula: MUST = BMI score (0-2) + weight-loss score (0-2) + acute disease effect score (0 or 2).
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Assign a score to each of three domains: BMI (>20 = 0, 18.5–20 = 1, <18.5 = 2), unintentional weight loss in the past 3–6 months (<5% = 0, 5–10% = 1, >10% = 2), and acute disease effect (if the patient is acutely ill and has been, or is likely to be, nil by mouth for >5 days = 2).
Add the three scores together. The total ranges from 0 to 6. This sum is the MUST score and determines the level of malnutrition risk.
Score 0 = low risk (routine re-screening at intervals). Score 1 = medium risk (observe, document dietary intake, repeat screening in 1 week for hospital, 1 month for care home). Score ≥2 = high risk (refer to dietitian, initiate nutrition support, treat malnutrition).
Nurses, doctors & allied health teams
NICE CG32 mandates nutritional screening on admission for all adult hospital patients. MUST is the most widely used and validated tool for this purpose in the UK NHS. Screening takes only 3–5 minutes and identifies the 25–34% of admissions at nutrition risk.
Care home staff & dietitians
MUST is validated for care home and community settings, not just hospitals. Residents should be screened on admission and monthly thereafter. Early identification allows targeted nutritional intervention before malnutrition becomes severe.
Community nurses & GPs
In outpatient and community settings, MUST guides whether a patient needs dietitian referral. A score of ≥2 in the community should prompt GP review and/or dietitian assessment within an appropriate timeframe.
Surgical teams & anesthesiologists
Malnutrition significantly increases surgical complications, infection risk, and length of stay. MUST screening before elective procedures identifies patients who may benefit from preoperative nutritional support (prehabilitation) to reduce operative risk.
Oncology dietitians & clinical nurses
Cancer-related anorexia, weight loss, and treatment side effects frequently result in high MUST scores. Serial MUST monitoring throughout treatment enables timely nutritional intervention, which is associated with better treatment tolerance and quality of life.
Unlike complex nutrition assessments, MUST is designed for rapid use by any healthcare professional, not just dietitians. It requires no specialist training. All ward staff can complete it on admission.
When direct measurement is impossible (e.g., bed-bound patients), estimate height from ulna length or knee height using validated conversion tables. MUAC (mid-upper arm circumference) can estimate BMI: MUAC <23.5 cm ≈ BMI <20; MUAC >32 cm ≈ BMI >30.
Any acutely ill patient who is nil-by-mouth or at high risk of being unable to eat for >5 days scores 2 for the acute disease effect item — regardless of their BMI or weight loss. This is the most commonly omitted item in clinical practice.
NICE Clinical Guideline CG32 (Nutrition Support for Adults, 2006) requires nutritional screening for all hospital inpatients using a validated tool such as MUST. This is a standard of care, not a recommendation.
Most NHS trusts specify that a MUST score ≥2 triggers a dietitian referral within 24–48 hours and initiation of a nutrition care plan. Always follow your institution's specific protocol.
BAPEN national audits consistently show that 25–34% of patients admitted to UK hospitals are at nutrition risk. Despite this prevalence, malnutrition is frequently under-recognized and undertreated without systematic screening.
A high MUST score indicates malnutrition risk based on anthropometrics and weight loss. It does not detect specific micronutrient deficiencies (iron, B12, folate, vitamin D) or assess the cause of malnutrition. Full dietitian assessment follows for positive screens.
When nutrition support is initiated following a high MUST score, enteral feeding (oral supplements, nasogastric, gastrostomy) is always preferred over parenteral nutrition when the GI tract is functioning. Enteral feeding preserves gut mucosal integrity and has lower infection risk.
The Mini Nutritional Assessment Short Form (MNA-SF) is specifically validated for elderly patients and includes functional and cognitive assessments that MUST does not. Consider MNA-SF for patients ≥65 years in geriatric settings.
The Nutritional Risk Screening 2002 (NRS-2002) is more widely used in European hospital settings and includes a disease severity adjustment. ESPEN guidelines recommend NRS-2002 for hospitalized patients. MUST and NRS-2002 have similar sensitivity/specificity for detecting malnutrition.
MUST developed by BAPEN (Elia, 2003). Validated across hospital, care home, and community settings. Inter-rater reliability κ=0.88. NICE Clinical Guideline CG32 (2006) mandates universal nutritional screening on hospital admission. Sensitivity for malnutrition ~85%, specificity ~75% vs SGA reference standard. BAPEN 2011 audits: 25–34% of hospital admissions are at nutrition risk.
A MUST score of 0 indicates low malnutrition risk and requires only routine re-screening at regular intervals. A score of 1 is medium risk and requires observation of dietary intake and repeat screening. A score of 2 or more indicates high risk, requiring referral to a dietitian, initiation of a nutrition care plan, and active treatment of malnutrition. In acutely ill patients, the acute disease effect item (which adds 2 points) ensures that any patient unable to eat for 5+ days is flagged as high risk regardless of their anthropometric status.
Use MUST on admission for all adult hospital patients as required by NICE CG32, and at regular intervals thereafter (weekly in hospital, monthly in care home, annually in community settings). It is particularly important in high-risk populations: elderly patients, cancer patients, post-surgical patients, those with GI disease, and anyone with recent unintentional weight loss. Screen obese patients too — high BMI does not exclude malnutrition risk from weight loss or acute illness.
MUST is a screening instrument only and does not replace full nutritional assessment by a registered dietitian. It does not identify specific nutritional deficiencies, quantify the degree of malnutrition, determine its etiology, or guide specific treatment. It also does not assess functional status, swallowing ability, or psychological factors affecting food intake — all of which are captured in more comprehensive assessment tools. In morbidly obese patients, the BMI component will always score 0, potentially underestimating risk if significant lean mass loss has occurred (sarcopenic obesity).
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
April 21, 2026 · trust-baseline
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