CDS (Clinical Dehydration Scale, Friedman JN et al., Pediatrics 2004) is a clinical scale for grading the severity of dehydration in young children (1 month to 3 years) with acute gastroenteritis and other fluid-losing conditions.
It includes 4 signs, each scored 0-2: general appearance (normal / restless / lethargic and unconscious), eyes (normal / slightly sunken / markedly sunken), oral mucosa (moist / sticky / dry), and tears when crying (present / decreased / absent). Total score 0-8.
Interpretation: 0 = no dehydration; 1-4 = moderate dehydration (~3-6% of body weight), oral rehydration is indicated; 5-8 = severe dehydration (≥ 7% of body weight), intravenous rehydration and hospitalization are indicated. The scale is simple, takes about 1 minute, and requires no laboratory data. WHO IMCI uses CDS as a standard assessment tool in primary care and emergency settings.
When to use
Child aged 1 month to 3 years with acute gastrointestinal infection, vomiting, or diarrhea.
Triage in the emergency department — decision between outpatient management and admission.
Decision on rehydration route (oral vs intravenous).
Serial monitoring during hospitalization — assessment of response to rehydration.
18-month-old girl with 2 days of vomiting and watery diarrhea (Bristol type 7). On examination: lethargic, drowsy, sunken eyes, dry mucous membranes, no tears when crying. Capillary refill 3 seconds, decreased skin turgor.
Severe dehydration (CDS 8, ~10% of body weight). Management: immediate hospital admission, intravenous rehydration — normal saline bolus 20 mL/kg over 20-30 minutes, reassess after the bolus; repeat the bolus if hypoperfusion persists. After stabilization, maintenance infusion (glucose-electrolyte solution) with deficit calculated as (weight × percent deficit × 10 = mL) over 24 hours. Monitor electrolytes, glucose, and urine output. If tolerated, transition to oral rehydration solution (WHO ORS).
Limitations and cautions
Validated for ages 1 month to 3 years; applicability is lower in older children.
Does not account for hypertonic dehydration (sodium > 150) — clinical severity may be worse than the CDS score suggests.
Sunken eyes may be a constitutional feature in some children.
Skin turgor assessment is difficult in children with obesity.
Frequently asked questions
Can dehydration be assessed clinically without laboratory tests?
For CDS 1-4, yes — laboratory testing is usually not required. For CDS 5-8, it is required: electrolytes, glucose, creatinine (especially if hyponatremia or acute kidney injury is suspected).
Oral rehydration solution vs intravenous rehydration?
For CDS ≤ 4, oral rehydration (WHO ORS with an osmolarity of 245 mOsm/L) is preferred. For CDS ≥ 5, or when oral intake is not possible (severe vomiting, altered consciousness), intravenous rehydration is used.
How often should the score be reassessed?
At 1, 2, and 4 hours after starting rehydration. A decrease in CDS indicates effective treatment.
Is CDS applicable in a child with DKA?
Use with caution. In DKA, dehydration is hyperosmolar, and rehydration requires a different approach (slower rate, risk of cerebral edema). Dedicated pediatric DKA protocols should be used.
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Aleksandr A. Aulov
Physician, internal medicine, Sechenov School — independent medical education platform.
Calculators are compiled from the original publications and current clinical guidelines. Interpretation thresholds follow the source study unless stated otherwise.
This calculator is intended for healthcare professionals. Do not use it for self-diagnosis or self-treatment. Management decisions are made by the treating clinician based on the full clinical picture of the individual patient.
Last clinical review: April 28, 2026 ·
Author: Aleksandr A. Aulov,
MD, internal medicine ·
Primary source: Goldman RD et al. Pediatrics 2008; 122(3): 545-549