How to interpret the CONUT score

The CONUT score ranges from 0 to 12 points. Higher scores indicate a worse nutritional status. The original publication defines four categories:

CONUT score	Nutritional status
0–1	Normal
2–4	Light malnutrition
5–8	Moderate malnutrition
9–12	Severe malnutrition

A raised CONUT score identifies patients who are likely to benefit from a full nutritional assessment. On its own it does not confirm the diagnosis of malnutrition.

What is the CONUT score?

The CONUT score (COntrolling NUtritional sTatus) is a screening tool for malnutrition in hospitalised patients. It was developed by Ignacio de Ulíbarri and colleagues at the Hospital Universitario de La Princesa in Madrid and published in 2005.

CONUT relies only on three routine laboratory values. Unlike questionnaire-based tools such as NRS-2002, MUST or the Subjective Global Assessment, it needs no interview, weight history or physical examination. It can therefore be calculated automatically from the hospital information system for every patient with available blood tests, which was the original purpose of the tool.

In the original validation in 53 hospitalised patients, CONUT showed good agreement with a full nutritional assessment (kappa 0.669) and moderate agreement with the Subjective Global Assessment (kappa 0.488). Using the full nutritional assessment as reference, sensitivity was 92.3% and specificity 85.0%.

Scoring table

Parameter	0 points	Light	Moderate	Severe
Serum albumin [g/dl]	≥ 3.5	3.0–3.49 (2 pts)	2.5–2.99 (4 pts)	< 2.5 (6 pts)
Lymphocytes [/µl]	> 1600	1200–1600 (1 pt)	800–1199 (2 pts)	< 800 (3 pts)
Total cholesterol [mg/dl]	> 180	140–180 (1 pt)	100–139 (2 pts)	< 100 (3 pts)

Albumin is weighted twice as heavily as the other two parameters, so a low albumin alone can move a patient into the moderate category.

Limitations

None of the three parameters is specific for malnutrition:

Albumin is a negative acute-phase protein. It falls during acute inflammation or infection and is also lowered by liver disease, nephrotic syndrome, protein-losing enteropathy and fluid overload.
Lymphocyte counts can be affected by infections, corticosteroids, chemotherapy, radiotherapy and haematological diseases.
Total cholesterol is lowered by statins and other lipid-lowering drugs, as well as by advanced liver disease and hyperthyroidism.

The CONUT score therefore reflects a combination of nutritional, inflammatory and immune status. Results should always be interpreted in the clinical context, and a positive screening result should be followed by a structured nutritional assessment, for example according to the GLIM criteria.

CONUT as a prognostic marker

Beyond malnutrition screening, the CONUT score has been studied extensively as a prognostic marker. Higher scores have been associated with worse outcomes in many malignancies (e.g. gastric, colorectal, lung and hepatocellular cancer) and in cardiovascular diseases such as heart failure and stroke. In these studies the score is often split into two or three groups, but the cut-off values differ between studies and patient populations. The interpretation shown by this calculator follows the original malnutrition categories by Ignacio de Ulíbarri et al.

Frequently asked questions

What is a normal CONUT score?

A score of 0 or 1 point corresponds to a normal nutritional status.

How do I convert SI units for the CONUT score?

Albumin: g/l ÷ 10 = g/dl (e.g. 35 g/l = 3.5 g/dl). Total cholesterol: mmol/l × 38.67 = mg/dl (e.g. 4.65 mmol/l ≈ 180 mg/dl). Lymphocytes: ×10⁹/l × 1000 = /µl (e.g. 1.6 ×10⁹/l = 1600/µl).

Does a high CONUT score mean that a patient is malnourished?

Not necessarily. CONUT is a screening tool. Inflammation, liver disease or medication can raise the score without malnutrition being present. A raised score should prompt a full nutritional assessment.

Can the score be calculated if one value is missing?

The calculator shows a partial score as soon as one value is entered, but a valid interpretation requires all three parameters.

What is the difference between CONUT and the Prognostic Nutritional Index (PNI)?

Both scores use serum albumin and the lymphocyte count. The PNI (10 × albumin [g/dl] + 0.005 × lymphocytes [/µl]) is a continuous value and does not include cholesterol, whereas CONUT assigns points in categories and additionally includes total cholesterol.

Reference

Ignacio de Ulíbarri J, González-Madroño A, de Villar NGP, et al. CONUT: a tool for controlling nutritional status. First validation in a hospital population. Nutr Hosp. 2005;20(1):38–45. Full text (PDF)

Written and medically reviewed by Frederic Eberhardt, MD. Last reviewed: 11 October 2026

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