Tachycardia is typically the first abnormal vital sign of hemorrhagic shock. As the body attempts to preserve oxygen delivery to the brain and heart, blood is shunted away from extremities and nonvital organs.

When cardiovascular changes occur, it could then cause tachypnea. Metabolic acidosis occurs when the acid level is too high in the blood, breathing rate increases to blow off carbon dioxide.

Rapid and substantial loss of blood or decreases in intravascular volume can cause dehydration. Transfusion should occur as soon as possible after life-threatening hemorrhage in order to keep the patient alive.

The body’s response to blood loss is compensatory in nature, resulting in progressive vasoconstriction of cutaneous, muscle, and visceral circulation, which preserves blood flow to the heart and brain.

High levels of epinephrine and other related hormones release to counteract the shock. Stimulation of the sympathetic nervous system will activate the sweat receptors in the skin, causing excessive sweating.

When the body begins to overcompensate, it will release non-vital fluids and chemicals stimulating the sympathetic nervous system causing nausea and/or vomiting.