According to the Office of National Statistics, the UK is the loneliness capital of Europe.
I think we can look at loneliness through the prism of nature's warning signs.
Like hunger is nature's way of telling us that we need food or pain that our body is sick or damaged and needs repair; feeling lonely tells us we need to connect.
Just last month, Helen Stokes-Lampard, Head of the Royal College of GPs, said that loneliness can be as bad for your health as a chronic long-term condition. Figures suggest it's as bad as smoking 15 cigarettes a day.
Loneliness could be quietly killing us and we're not talking about it.
One person did talk about it though - my friend and colleague Jo Cox. For Jo, however big and complex a problem was, there was always a solution.
Jo came into Parliament in 2015, wanting to do something about loneliness. For her it was personal. Jo's grandad was a postman. And as a young girl, Jo would accompany him on his rounds, stopping and chatting to people as he delivered their post. Jo came to realise that for some people that conversation with her grandad might be the only interaction they had that entire day.
Then when Jo went to university she experienced loneliness first-hand. She missed her friends and family, particularly, her sister Kim, with whom she was so close and took a while to make real friends.
And through her work and later, campaigning in Batley and Spen, knocking on doors and attending community events, she saw how many people were lonely and how loneliness was a lived reality for too many people.
Jo is well-known for her talent in bridging political divides and building cross-party alliances. She teamed up with Seema Kennedy, Conservative MP for South Ribble to establish a Commission on Loneliness, bringing together 13 organisations. After Jo's murder, Seema reached out to me and we embarked on a year long piece of work in Jo's name. I am incredibly proud to be able to take forward Jo's work with her friends, family, colleagues and all the people she inspired.
I have been truly shocked by some of the statistics. One of our partners, Sense, found that one in four of us admitted to avoiding conversations with disabled people, because they think they don't have anything in common with them.
While Carers UK surveyed carers around the country and found the sobering statistic that eight out of 10 carers have felt lonely or isolated as a result of looking after a loved one. Action for Children for their spotlight which launched last week found that half of parents had experienced loneliness.
It is for all of us to act. So in December the Commission will be publishing a manifesto with some key recommendations - for Government, business but for society as a whole too.
Under the #HappytoChat slogan we have been working to challenge the idea - whether it is perceived or real - that you need permission or some kind of excuse, like a power cut or unusual weather, to talk to one another. We need to be thinking more about how we break down these rules we see to have made for ourselves.
One of the ways that can start is with our communities coming together.
This summer 9.3million people took part in the The Great Get Together to support Jo's message that we have 'more in common than that which divides us'. The Great Christmas Get Together will call on the public to take small acts to build strong communities this Christmas by sharing a mince pie with a neighbour, acquaintance or friend.
On Wednesday 15 November, I have secured a Westminster Hall debate on loneliness. MP from all parties will speak about the impact of loneliness on our communities and the many community projects that are tackling loneliness. Like Jo always said, we have more in common than that which divides us. Starting a conversation with our neighbours, colleagues, acquaintances or someone waiting with you in a queue is something we can all do to reduce loneliness.
Rachel Reeves is the Labour MP for Leeds West