Loneliness is more than simply being alone—it is the distress that comes from a perceived lack of meaningful connection. Chronic loneliness has been linked to depression, anxiety, and reduced self-esteem. On a biological level, it increases stress hormones like cortisol, which can weaken immunity, raise blood pressure, and contribute to heart disease. Persistent loneliness may also impair sleep and cognitive function. Social connections act as a buffer against stress, giving individuals emotional support and a sense of belonging. Building supportive relationships, joining community activities, or seeking therapy can help counter loneliness and protect both mental and physical health.