Christmas can be agony for parents whose children have been missing for years.
It's 21 years since John and Anne Mills' son, Kevin, walked out one morning and never returned.
Anne Mills, from Yaxley near Peterborough, said: "Everywhere you go you're looking at faces to see if he might just see him.
"When people ring up you just can't help it really. Just something you've got to live with and at least people are trying to see him."
Kevin had been in the Navy and has no idea he has nephews and nieces
John Mills said: "It is hard. I mean he may have another life. He may even have children we don't know about. You do think about that, it's hard."
Click below for Kate Prout's report
But not everyone disappears through their own choice. Nicki Durbin has spent 11 years trying to find out what happened to her son, Luke, when he went missing on a night out in Ipswich in 2006.
She admits she thinks he may no longer be alive. But she needs to know, one way or another.
Nicki Durbin said: "All the time we talk about Luke. And i think, even if he's been taken, no one can take our memories of Luke. It's really important to keep talking about him.
"Obviously the sad thing is there's no new memories. There haven't been any new memories for 11 and a half years."
Luke should have celebrated his 30th birthday this week. Instead his family face another Christmas without him.
Nearly 150,000 people go missing every year. The majority of those will return or be found within 24 hours with only 2% remaining missing for more than a week.
The reasons people deliberately go missing are complex. With children it's usually problems at home but for adults it can be trying to escape from relationships, money or their own wellbeing.
Up to eighty per cent of people who go missing have mental health problems.
Police forces use a lot of resources searching for missing people depending on the circumstances. Even if that person wants to disappear.
Det Supt Eamonn Bridger from Suffolk Police said: "There are some people who don't want to be found and a variety of reasons as to why that may be the case.
"That said, we have to respect that other professionals or their loved ones may have a different interpretation and know the vulnerabilities that that individual faces.
"And as a public agency, it's obviously core to policing that we look to protect the vulnerable."