What happens to your body if the system/organs fail?

Organ failure: The failure of an essential system in the body. Multiple organ failure is the failure of two or more systems, such as the cardiovascular, and renal systems, and is a common consequence of sepsis (the presence of bacteria in the bloods) and of shock (very low blood pressure).
The symptoms depend on what organ system is failing (heart, liver, kidney, brain)- but can include:
Shortness of breath
Fatigue
Loss of appetite
Increased heart rate
Yellowing of the skin
Excessive weakness
Easy bruising
Edema/fluid retention
Pain in chest
Anemia
Consciousness gets disturbed
Reduction in the ability to focus
Increased stress