The different types of shock are characterized by the same clinical signs.

A. Hypotension
Hypotension in adults is traditionally defined as a systolic blood pressure of 90 mm Hg or less but must be evaluated relative to the patient’s normal blood pressure. Whereas a systolic blood pressure of 90 mm Hg may be normal in a healthy, athletic adult, a pressure of 100 mm Hg may indicate shock in a patient who is normally hypertensive. A drop in systolic pressure of more than 10-20 mm Hg and an increase in pulse of more than 15 with positional change suggest depleted intravascular volume. Orthostatic hypotension resulting from peripheral neuropathy or use of ß-blockers is usually not associated with an increase in pulse rate.

B. End-Organ Hypoperfusion
Patients in shock often have cool or mottled extremities and weak or absent peripheral pulses. Splanchnic vasoconstriction leads to oliguria, bowel ischemia, and hepatic dysfunction, which can ultimately result in multiorgan failure.

C. Altered Mental Status
Patients may demonstrate normal mental status or may be restless, agitated, confused, lethargic, or comatose as a result of inadequate perfusion of the brain.