Loneliness isn’t just an uncomfortable feeling; it’s a public health crisis that rivals smoking in its deadly impact. Despite our hyper-connected digital age, rates of loneliness continue to climb alongside anxiety and depression.
This exploration of the consequences of social isolation and loneliness draws primarily from Vivek Murthy’s insights in Together, supplemented by Johann Hari’s findings in Lost Connections, to examine why social isolation triggers such devastating consequences. Keep reading to understand the hidden cost of loneliness and why addressing loneliness requires both personal awareness and systemic change.
Table of contents
The Consequences of Loneliness
Our evolutionary hardwiring for connection explains why lacking meaningful relationships profoundly affects our well-being. Murthy explains that when we’re socially disconnected, our bodies and minds respond as though facing a survival threat. (Shortform note: While loneliness may no longer pose the same physical threat it did to early humans, it continues to be a survival threat—social isolation increases the risk of premature death by 29%.)
The Physiological Response to Loneliness
Loneliness leads to harmful physical changes: Your brain interprets prolonged social isolation as a threat, which triggers the release of cortisol and other stress hormones. These stress hormones are bad for your health in a number of ways—for example, they suppress immune function, increase inflammation, and raise blood pressure.
(Shortform note: Studies show that mindfulness-based stress reduction programs help relieve the physical health effects of loneliness. This may be because mindfulness calms the body’s stress response, helping your brain learn to not respond so severely to loneliness. Mindfulness also encourages self-awareness without judgment, which helps you perceive moments of loneliness more neutrally, further dampening your body’s response to lonely feelings. Furthermore, as psychologist David Richo argues in How to Be an Adult in Relationships, mindfulness promotes relationship health, which may help break the cycles of disconnection that cause loneliness and related physical health outcomes in the first place.)
The Long-Term Health Impacts of Loneliness
According to Murthy, loneliness strongly predicts poor health outcomes and earlier death. Studies show that lonely people experience worse sleep, faster cognitive decline, and reduced stress resilience. Research suggests chronic loneliness is as harmful as smoking 15 cigarettes daily—more dangerous than obesity, alcoholism, or physical inactivity. People who are chronically lonely face a 26-32% higher risk of dying early compared to those with strong social connections, even when accounting for other health factors.
(Shortform note: While many countries have established public health campaigns against smoking, loneliness remains largely unaddressed despite carrying similar mortality risks. Anti-smoking campaigns have dramatically reduced smoking rates through public awareness, policy changes, and support programs. A similar campaign for loneliness could be equally effective. The UK has pioneered this approach with its Ministry of Loneliness, established in 2018. This government body funds community spaces, outreach programs, and education initiatives to reduce stigma around loneliness, demonstrating how addressing social disconnection can be elevated from individual concern to systematic public health strategy.)
Loneliness also worsens or causes many mental health problems, with studies linking chronic loneliness to higher rates of depression, anxiety, and suicidal thoughts. The relationship works both ways—loneliness can trigger mental health issues, while mental health conditions can further isolate people, creating a harmful cycle.
(Shortform note: The bidirectional relationship between loneliness and poor mental health makes recovery more difficult for those with mental health conditions. Depression diminishes the ability to enjoy social connections, while anxiety heightens fear of rejection, both leading to withdrawal. These internal barriers combine with external factors like mental health stigma and limited treatment access to deepen isolation. The result is a self-reinforcing cycle where loneliness and mental health problems continuously intensify each other, making intervention essential to break this pattern and restore health.)
| We’re More Connected Than Ever…Or Are We? In Lost Connections, Johann Hari argues that our lack of meaningful connections due to modern lifestyles are major drivers of anxiety and depression, and therefore, our medical model of psychiatric care is insufficient for treating the problem at its root. His solutions mostly focus on large-scale systemic social changes, but he also suggests that on an individual level, it’s important to recognize that making online connections isn’t enough. Modern humans tend to think we’re more connected than ever because of our online networks and constant interactions, but despite this, levels of anxiety, depression, and loneliness are higher than ever. This clearly indicates that we need to actually get out and talk to people, face to face, as our evolutionary urge to be in connection with others depends on that physical presence. On the other hand, in Mind Over Medicine, Lissa Rankin says if you surround yourself with people that make you feel accepted, loved, and uplifted, you’ll feel relaxed and promote healing. To demonstrate the healing power of positive support, Rankin references a study that observed the influence of relationships on the recovery of 3,000 nurses with breast cancer. Those who had 10 or more friends supporting their recovery were four times less likely to die from their diagnosis. |
The Impacts of Loneliness on Social Structures
Murthy says that the collective economic burden of loneliness extends far beyond personal suffering, creating substantial costs for health care systems and workplaces. Research shows that people who are lonely stay 64% longer at hospitals, visit the emergency room 29% more often, and are more likely to be placed in nursing homes when compared to more socially connected peers with similar health conditions. In the workplace, chronic loneliness manifests through higher absenteeism, decreased engagement and productivity, increased disability claims, and earlier retirement.
(Shortform note: Economic arguments have shifted loneliness from a “soft” issue to a policy priority. Loneliness costs Medicare $6.7 billion annually, and the costs of loneliness in the workplace exceed $154 billion. These figures help policymakers secure funding for community-building programs, which show strong returns on investment by reducing healthcare use and improving employee engagement and retention. However, the economic benefits of loneliness interventions are only one piece of the puzzle. While cost savings may influence policy decisions, the emotional and social value of belonging is just as important—even if it’s harder to measure.)
Learn More About the Effects of Social Isolation
To better understand the consequences of loneliness and its broader context, check out Shortform’s guides to the books we’ve referenced in this article:
