What's the difference between septic shock and hypovolemic?

The cause. Septic shock is shock due to bacteria in the blood stream, causing sepsis. Hypovolemic shock is due to low volume, usually blood loss.
Causes of shock. Hypovolemic shock is shock (inadequate tissue perfusion) due to decreased fluid volume in the blood vessels (usually from bleeding or severe dehydration). Infection can lead to septic shock: systemic vasodilation (blood vessels relax->blood pressure drops) and/or capillary leak (fluid shifts out of the blood vessels, causing hypovolemia) and/or metabolic cardiomyopathy (decreased heart function).