Severity Assessment

Diagnosis Alone Is Not Enough

Same Disease · Different Severity · Different Action Stable or Unstable? Severity Determines Urgency
Reminder

Common diseases are common —
but not all cases are equal.

The gap Loose motion is common. Asthma is common. Fever is common. But within each diagnosis lies a spectrum — from mild and self-limiting to immediately life-threatening.
The skill Knowing the diagnosis is necessary. Knowing the severity is what drives the decision. Without severity assessment, management is blind.
Your job To know the difference between a patient who needs reassurance and a patient who needs resuscitation — sometimes with the same diagnosis.
The Midnight Phone Call

Same diagnosis — completely different call

Call without severity
House Officer "Doctor, there is a patient with loose motion."
Consultant "So what?"
No urgency communicated. No action triggered.
Call with severity
House Officer "Doctor, there is a child with loose motion — hypotension, delayed capillary refill, tachycardia, and altered sensorium."
Consultant "Resuscitate immediately. Admit. I am coming in."
Resuscitate immediately — admit now.
Same diagnosis. Different severity. Completely different management.
The second house officer did not know more medicine — they communicated severity.
Core Principle

Severity determines four things — always

⚡

Urgency

How fast must you act? Minutes, hours, or days?

🏥

Location of Care

Home, ward, HDU, or ICU?

💊

Intensity of Treatment

ORS or IV fluids? Inhaler or nebuliser and oxygen?

📊

Prognosis

What is the expected outcome and risk of deterioration?

Examples

Diagnosis ≠ Severity — the same disease, two completely different patients

Example 01

Acute Gastroenteritis

Mild

Mild dehydration. Alert. Drinking well.

→ Oral rehydration solution at home.

Severe

Severe dehydration with shock. Hypotension, altered sensorium, delayed capillary refill.

→ IV fluids, immediate resuscitation, admission.

Example 02

Asthma

Mild Attack

Mild wheeze. Normal SpO₂. Speaking in sentences.

→ Inhaled bronchodilator. May discharge.

Severe / Near-Fatal Attack

Hypoxia. Accessory muscle use. Unable to complete sentences. Silent chest.

→ Oxygen, nebulisation, IV steroids, possible ICU.

Red Flags

General features of severe illness

🫀

Haemodynamic Instability

Circulation
↓
Hypotension Late sign in children — decompensation has occurred
↑
Tachycardia Early and sensitive sign — do not normalise it without explanation
↑
Prolonged capillary refill (>2 seconds) Indicates poor peripheral perfusion
↓
Reduced urine output Reflects renal perfusion — a proxy for cardiac output
↓
Cool extremities / mottled skin Peripheral vasoconstriction — compensatory response
🫁

Respiratory & Neurological Failure

Airway · Brain
↑
Tachypnoea / increased work of breathing Accessory muscle use, nasal flaring, subcostal recession
↓
Hypoxia (low SpO₂) Oxygenation is failing — immediate action required
↓
Altered consciousness / GCS Reduced perfusion or oxygenation to the brain
↓
Abnormal tone or posturing Neurological deterioration — urgent assessment needed
!
Silent chest in asthma No air entry = no wheeze — this is a pre-arrest state
Beyond Clinical Impression

Formal severity scoring tools

The general principles above are the foundation. In practice, many common diseases have validated severity scoring systems that operationalise these principles into reproducible criteria. These tools exist because clinical impression alone can be unreliable — particularly under time pressure or for less experienced clinicians.

You are not expected to memorise every scoring system. You are expected to understand that structured severity assessment — whether clinical or tool-assisted — is always part of management, not an optional extra.

WHO Dehydration Scale Gastroenteritis / dehydration
GINA / BTS Severity Acute asthma
PEWS Paediatric Early Warning Score
SOFA / qSOFA Sepsis severity
Glasgow Coma Scale Neurological severity
Priority

Management priority framework — severity answers all four

1
Is this patient stable or unstable?
If unstable → act now before anything else
2
Does this require immediate resuscitation?
If yes → resuscitate before investigating
3
Does this require admission?
Ward, HDU, or ICU depending on severity
4
Can this be safely managed as an outpatient?
Only if stable, no red flags, reliable follow-up
The Presentation Rule

Every case presentation must include severity.

Diagnosis
+
Severity
+
Stability
=
Clinical Maturity
"Moderate dehydration" due to acute gastroenteritis.
"Severe acute asthma" with hypoxia and accessory muscle use.
"Compensated heart failure" — haemodynamically stable on current therapy.
"Septic shock" — unresponsive to initial fluid resuscitation.
Common Student Errors

What severity-blind thinking looks like

Presenting a diagnosis without any severity descriptor
Focusing on the diagnosis while ignoring the vital signs
Waiting for hypotension before recognising shock in a child
Not reassessing after initial treatment to detect deterioration
Final Take-Home Message
"Diagnosis tells you what the patient has.
Severity tells you what you must do now."

In real medicine, severity often matters more than the label.
Assess severity first. Then manage accordingly.

Stable or unstable? Compensated or decompensated? Always include severity
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