Social isolation is a term often used interchangeably with loneliness, but while the two are closely related, they do not necessarily mean the same thing.
You can be lonely in a crowd, but you will not be socially isolated. Isolation has been defined as an objective state whereby the number of contacts a person has can be counted, whereas loneliness is a subjective experience. While the terms may have slightly different meanings, both can be painful experiences and have harmful impacts at the individual and societal levels.
Social isolation describes the absence of social contact, and can lead to loneliness. It is a state of being cut off from normal social networks, which can be triggered by factors such as loss of mobility, unemployment, or health issues. Isolation can involve staying at home for lengthy periods of time, having no access to services or community involvement, and little or no communication with friends, family, and acquaintances.
There are many contributing factors to social isolation. People can be prevented from leaving the house and having contact with other members of society due to long-term illness, disabilities, transport issues, unemployment and economic struggles, or domestic violence.
Some may be physically able to go out and meet people, but are inhibited from doing so by factors such as depression, social adversity, becoming a carer for a loved one, or bereavement. Any of these factors can be barriers to forming and maintaining social networks, and can lead to loneliness and isolation.