Hypovolemia and Hypovolemic Shock: Stages, Causes, Symptoms and Treatment

Hypovolemia is characterized by the loss of a large amount of blood and / or fluids, especially plasma, which can lead to death in a matter of minutes.

The hypovolemic shock refers to a medical or surgical condition in which fluid loss occurs rapidly resulting in multiple organ failure due to inadequate perfusion.

Most hypovolemic shocks are secondary to rapid blood loss (hemorrhagic shock).

Thus hypovolemia leads to tissue hypoperfusion , with imbalance in the supply of oxygen and energy substrates that can cause tissue damage and lead to death.

Therefore, the shock (shock) is characterized clinically by the combination of hypotension. Hypovolemic shock can be classified into 4 stages according to the percentage of blood loss:

Stage I
It occurs when up to 15% of the circulating volume is lost, that is, approximately 750 ml of blood. These patients often have few symptoms, since the compensation mechanisms support bodily functions.

Stage II
It occurs when 15% to 30% is lost, or up to 1,500 ml of circulating volume blood. These patients have subtle signs of shock, but the vital signs remain normal.

Stage III
Occurs when 30% to 40% of the circulating volume, or 1,500 to 2,000 ml of blood is lost. This patient looks pretty sick.

Stage IV
The most severe form of hypovolemic / hemorrhagic shock. This patient has lost more than 40% of the circulating blood volume, or at least 2,000 ml of blood, and is at risk of bleeding.

Complications of hypovolemic shock include adult respiratory distress syndrome, sepsis, acute renal failure, disseminated intravascular coagulation, stroke, and multiple organ dysfunction syndrome.

Causes of hypovolemia

Penetrating trauma or severe gastrointestinal disorders are two common causes of hypovolemia. Other causes of hypovolemic shock can be extensive burns, diuretic or vasodilator poisoning, severe diarrhea, vomiting, and severe inflammation.

Hemorrhagic shock can also be the result of significant loss of blood in the internal cavity in the chest and abdomen.


The patient shows a fall in blood pressure, increased heart rate and respiratory, cold limbs, cold and pale skin, excessive tiredness and weakness, dilated capillary area, excessive sweating, venous collapse, anxiety and nervousness, tachycardia, postural changes, hemodynamic instability and deterioration of the mental state (coma).

Treatment of Hypovolemic Shock

For its treatment it is recommended the correction of the Arterial Pressure , to improve the O2 offer, to start in the test volume and to install basic monitoring, the interventions that are vital for a good prognosis.

The replacement of fluids (blood and plasma) should be done as soon as possible, through the transfusion of blood and / or the administration of saline solution in the vein.