Loneliness in the UK is an epidemic affecting people of all ages and backgrounds, according to a commission started by the murdered MP Jo Cox.
But if you find yourself feeling lonely, what can you do about it?
For many people, loneliness is not solved overnight - but people from all walks of life, including single fathers, millennials in a new city, widows, teenage mothers, and happily married husbands, have told the BBC their tips for making their days a bit brighter.
Learn something new - in real life or on the internet
"At St John Fisher Church in North Harrow, we started a knitting group for ladies at home to get together over a cup of tea and knit for charities. We laugh and chat all afternoon." - Teresa Arrigo
"My saving grace was the internet - I found a group for widowed people called Way Up (for the over-50s. Way is for the under-50s). The group showed me that after I was widowed I discovered that, despite people expecting me to get over it, all the different emotions I experienced were normal and OK." - Angie Cole
"My lifesaver is the internet - websites for counting penguins and watching a guy and his chicken sail around the world." - Diane Keel
Take a long walk or pump some weights
"I am a single dad. My loneliness hit me when I had to sell the business to look after my young children full-time. What helps now is going to the gym and a bit of voluntary work while the kids are at school." - Qamar Qureshi
"I am often lonely. I am currently in the USA as my husband is on secondment and knew no-one when we arrived. I cannot work, so the days are long. The solution for me is to get out, even if it's only for a walk - it helps as you usually see someone to say hello to. I also joined a gym, which gives structure to my week." - Helen Stenson
"I am a mum of two young children, and I definitely found that going to baby groups when they were little and mixing with other parents helped me to stop feeling as lonely. I still try to go to groups with them now, when I can. As much as you might not feel like going out, it does help, and it feels like a real achievement when you do, so that is a boost too." - Emily Holbrook
Spend time with your cat (or pet of choice)
"I am 79 years old and was always feeling lonely in the evenings - I told my daughter that I would like a kitten, so she searched a cat sanctuary and I chose a little black one and called him Barney. He was eight weeks old when I got him, and he has completely changed my life around because he wants attention all day. I cannot imagine my life now without him. I am disabled but manage to look after him very well, and he is a happy little boy of five months." - Joan Gutteridge
"My cat - she is a constant companion at home and a real comfort. I have to keep going to make sure she has everything she needs, and she relies on me as her significant other. She has become more cuddly, which I find makes me happy." - Kerry Williams
Volunteer for a charity
"When I reached rock-bottom, I signed up to volunteer for two charities - one helping disadvantaged families and children, and the other in conservation work. I also joined a community choir, got an allotment - and adopted a cat. I am beginning to feel a lot more connected to my community, and a lot less lonely." - Nancy Saunders
"I offered my time to Age UK, and I help in a day centre. I've met lovely people, and, even better, I'm giving something to the community." - Ruth
Join a club or networking group
"Self-employed people like me struggle. I worked as a video producer and TV repair person from home for over 20 years. I employed a part-time co-worker, scheduled meetings with other professionals once a month, joined a networking breakfast group, joined a gym for badminton classes, joined a club (in my case a video club) - any excuse to meet up, especially with other like-minded professionals." - David James
"Join the University of the Third Age. It is a collection of older people who want to follow new interests or carry on with existing ones. There are groups for cycling, motorcycling, cooking, languages, sewing. The list is endless - all you need to do is contact their local group, you will be given a warm welcome." - John Watts
"My advice would be find your local toddlers' club. I now attend one with my grandson and have made new friends. Also join the library - ours has great children's story times." - Nina Kent
"A few months ago, I came across a phone app called Meetup. It's changed my life already. I've been on a few 'meetups' and met some lovely groups of normal people. I've been on walks, quiz nights, [a] comedy show, booked a weekend in Cornwall and even started Kung-fu." - Keith Littlebury
"I use the internet to overcome loneliness - I use YouTube for music, documentaries and stand-up comedy. Laughing helps a lot." - Kerry Williams
Produced by Annie Flury and Georgina Rannard, UGC and social news