Acute stress is a kind of stress where an individual is put in a high-risk situation, which requires all of the mental and physical resources of the body to overcome. These types of situations include avoiding a car-crash, engaging in a violent conflict with another person, being surprise-scared, and so forth. They typically do not last beyond the encounter and are relatively infrequent, hence why they are defined as short-term stressors. A person can overcome acute stress fairly quickly, after the danger has passed.
Chronic stress, on the other hand, appears when a patient is constantly exposed to the source of stress, which may be that of an acute or less intense nature. Chronic exposure to acute stress can lead to severe forms of psychological disorders, such as depression and PTSD. This type of stress can negatively affect one’s health in the long-term and requires extended treatment to overcome.