lonely man in physical pain

The physical impact of loneliness (Part 1)

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By Kim O’Neill, CEO, On the Line

Thanks to extensive research and a growing chorus of voices, loneliness is slowly becoming recognised as a genuine public health challenge, perhaps THE public health challenge of our times. Some have called it an ‘an epidemic’ and while this may seem alarmist, talking about the threat of loneliness in these terms is no exaggeration.

Its well-recognised that loneliness plays a significant role in causing and exacerbating emotional difficulties, but recent research into loneliness has also led to a greater understanding of how it can ravage our bodies.

Prominent researchers like Julianne Holt-Lunstad from Brigham Young University have found that insufficient social connection is a bigger risk factor to health than obesity and poses the equivalent risk to health as smoking up to 15 cigarettes a day. Researchers like Julianne are helping to put some more hard evidence behind what many health professionals have known for decades – loneliness is a serious health threat.  As former U.S. Surgeon General Vivek Murthy once said, the most common affliction he saw during his years of service “was not heart disease or diabetes; it was loneliness.”[1]


Loneliness as a disease

As researchers look more closely at the inner workings of the body, including cells and nerves, they are confirming that loneliness does not just affect our emotions, it has clear and identifiable impact on our bodies. In a way, these discoveries are just as important and far-reaching as the germ theory of disease – for many years, we have suspected that loneliness plays a big role in physical illness and even early death, but haven’t been able to explain how. But all that is changing.

‘Psychobiologists can now show that loneliness sends misleading hormonal signals, rejigs the molecules on genes that govern behavior, and wrenches a slew of other systems out of whack. They have proved that long-lasting loneliness not only makes you sick; it can kill you.'[2]

The analogy of disease is also a useful one to understand the magnitude of the loneliness problem. Just like a disease, the core ‘illness’ of loneliness can lead to a number of tangible physical symptoms and perhaps even more startling, evidence is growing that loneliness can be contagious, in studies conducted by researchers Cacioppo, Christakis and Fowler.

Why does loneliness have such a big effect?  There’s a few reasons, but in part it’s because it triggers our stress response, that when activated for prolonged periods, can have enormous negative effects on our health.  We know that when stress responses remain activated for long periods they can play havoc with our wellbeing, as they suppress the function of our immune systems and raise levels of the hormones cortisol and epinephrine; which contribute to inflammation and weakened immunity. This makes us more vulnerable to infection and puts us at increased risk for developing all kinds of illness and diseases.


Physical ailments related to loneliness

Loneliness contributes to seemingly countless health woes, as it not only makes us more susceptible to catching viruses, but has been shown to worsen symptoms of many ailments.

A short list of just some of the physical ailments thought to be caused or worsened by loneliness includes:

  • Poor cardiovascular health and heart disease
  • Stroke
  • Obesity
  • Neurodegenerative diseases such as Alzheimer’s
  • Diabetes
  • High blood pressure
  • Cancer—tumors can metastasize faster in lonely people
  • Respiratory illnesses like the common cold
  • Aches, pains and headaches
  • Diet problems such as loss of appetite, sudden weight gain or loss.

With more and more information becoming available about how loneliness affects us and a growing evidence base, we need to ensure that it remains a central topic in any discussion on public health and continue to push for loneliness to be tackled at the highest levels of our society.  



[1] https://theconversation.com/a-history-of-loneliness-91542

[2] https://www.vichealth.vic.gov.au/letter/articles/vh-letter-47-loneliness