Summary: Shock happens when not enough blood and oxygen can get to your organs and tissues. It causes very low blood pressure and may be life threatening. It often happens along with a serious injury.There are several kinds of shock. Hypovolemic shock happens when you lose a lot of blood or fluids. Causes include internal or external bleeding, dehydration, burns, and severe vomiting and/or diarrhea. Septic shock is caused by infections in the bloodstream. A severe allergic reaction can cause anaphylactic shock. An insect bite or sting might cause it. Cardiogenic shock happens when the heart cannot pump blood effectively. This may happen after a heart attack. Neurogenic shock is caused by damage to the nervous system. More >> Less >>

Reference Material:
https://medlineplus.gov/shock.html