How can factors that are capable of influencing people both negatively and positively be classified

Internal and external factors

Explanation:

If we talk about health factors they are the elements which are able to affect the behavior or overall health of a person in several ways. The effects can both be positive or negative depending on the nature of the factors.

These factors can broadly be described into two main categories:

Internal factors are those over which a person do not has alot of control, such as genetic makeup, some bad habits developed over the long period of time etc. These provoke the individual to go for some specific behavior from inside him.

On the other hand, external factors are those that provoke the individual from outside, for example his environment, the habits of people with whom he interact etc. For example: A dirty and polluted environment pose threat and risks for individual's health.

Hope it help!