# Risk

**DOI:**https://doi.org/10.1007/978-1-4020-5614-7_3029

## Synonyms

Absolute risk

## Definition

There are two commonly used terms associated with risk assessment. They are hazard and risk. A risk is the likelihood that exposure to a hazard will result in injury or disease. In risk assessment , risk combines the probability of an event occurring with the impact that event would have under different circumstances. The level of risk can be viewed as a function of probability and severity of impact.

Risk is the probability that a risk event, such as disease, injury, disability, or death, will occur during (over) a specified time period. For calculation of risk, the numerator contains the number of persons experiencing the risk event during the time period. The denominator contains the population at risk, i. e. the number of persons who are free of the risk event at the beginning of the time period, but capable of having disease.

Variables associated with an increased or decreased risk are the risk factor or protective factor, respectively. The...