Shock: the clinical signs and the types !

Syndrome

Shock means the blood cannot deliver enough oxygen to the organs; it shows in the skin, the mind, the urine and the pulse.

Updated 2026-11-01

See it in 3D: Left ventricle · Inferior vena cava · Pericardium

What it is

Shock is acute circulatory failure with tissue hypoperfusion. Hypotension can come late: the first signs are tachycardia, cool skin, slow capillary refill, oliguria and confusion. Examining the neck veins, lungs and skin points to the type.

Key findings

Hypotension: systolic below 90 mmHg or mean arterial pressure below 65 mmHg, or a marked fall from baseline.
Tachycardia, weak pulse, tachypnea, capillary refill over 2 seconds, cool, pale, sweaty or mottled skin.
Oliguria (less than half a milliliter of urine per kilogram per hour) and altered mental status.
Shock index (heart rate / systolic pressure) above 1: hypoperfusion likely.
Flat neck veins: hypovolemic or distributive. Distended neck veins: cardiogenic or obstructive. Crackles: cardiogenic. Warm skin early: septic.

Pathophysiology

Blood pressure = cardiac output times vascular resistance; shock appears when one falls and the other cannot compensate.
Hypovolemic: not enough volume (bleeding, dehydration). Cardiogenic: the pump fails. Obstructive: something blocks filling or outflow (tamponade, tension pneumothorax, massive embolism).
Distributive: vasodilation with maldistributed flow (septic, anaphylactic, neurogenic).
The sympathetic response gives tachycardia, vasoconstriction and cool skin; anaerobic metabolism raises lactate.

Common causes

Hypovolemic: bleeding from trauma, the gut or childbirth; diarrhea and vomiting; burns.
Cardiogenic: large infarction, arrhythmias, myocarditis, acute valve disease.
Obstructive: cardiac tamponade, tension pneumothorax, massive pulmonary embolism.
Distributive: sepsis, anaphylaxis, spinal cord injury (neurogenic, with bradycardia and warm skin).

Tests that confirm it

Raised lactate; arterial blood gas with metabolic acidosis.
Bedside ultrasound: cardiac function, pericardial effusion, vena cava, pneumothorax.
Beta-blockers, pacemakers and old age can mask tachycardia; children and young adults keep their blood pressure until late.

Test yourself

Think of the answer, then tap the question to see it.

Which types of shock present with distended neck veins?

Cardiogenic and obstructive (tamponade, tension pneumothorax, massive embolism).

Why is hypotension a late sign of hemorrhagic shock?

Tachycardia and vasoconstriction hold blood pressure up until a large part of the volume is lost.

Which combination of signs suggests neurogenic shock?

Hypotension with bradycardia and warm, dry skin after a high spinal cord injury.

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See it in 3D

The structures of Durgical's 3D anatomy where it is found.

← All of the clinical exam

Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.

Sources: Shock: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); Cardiac tamponade: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); 24.3 Nursing Assessment - Clinical Nursing Skills | OpenStax (OpenStax (Rice University), 2024).

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