Social isolation is a complete or near-complete lack of contact between an individual and society. It differs from loneliness, reflecting a temporary and involuntary lack of communication with other humans. Social isolation can be an issue for individuals of any age, though symptoms may differ by age group.

Social isolation has similar characteristics in both temporary instances and for those with a historical lifelong isolation cycle. All types of social isolation can include staying home for lengthy periods, having no communication with family, acquaintances or friends, and avoiding contact with other humans when those opportunities arise.

True social isolation over the years and decades can be a chronic condition affecting all aspects of a person's existence. For example, social isolation can lead to feelings of loneliness, fear of others, or negative self-esteem.