Research by relationship support organisation Relate shows that 15% of parents feel their teenagers' behaviour is 'out of control' and around one in 10 aren't confident when dealing with their teens.

"Lots of teens test parents' boundaries, and when things get tough it can lead to real problems for families," says Ruth Sutherland, Relate's chief executive.

Relate has launched a free online service for parents who are worried about their teens.

"We want to help as many parents as possible understand their teenagers better, in order to build and maintain strong relationships, reducing strain on the whole family."

The Relate poll found almost one in five parents weren't confident they knew what was going on in their teen's life.

Try to remember what it’s like to be a teenager

Chris Sherwood, Relate's director of policy and external affairs, points out that as well as parents trying to remember what they felt like as teenagers, it's important to think about what it's like to grow up today, especially with all the new technology.

While the internet brings opportunities, it also means new threats and concerns with issues like cyberbullying.

"It's important that parents try to understand their teenager's worries, because those worries are going to be different from their own experience," he says.

"Understand what's going on in their lives, and remember that sometimes it's not the teenager at fault - there are two parts to the relationship, the parent and the teen, and both can change their relationship by behaving differently."

Talk to your teen

It's critical for parents to make an effort to talk to their teenagers, and plan quality time together, Sherwood stresses.

"It's not just about teenagers not communicating with their parents, it's also about how parents communicate with teenagers."

It's important that parents know there's support available, where they can share their worries. "It can feel like a very lonely experience when you have a teenager and your relationship is difficult," says Sherwood. "But help and support is available both for the parent and the teenager."

Remember…

Counsellors offer impartial support, helping people understand what's going on, what's going well and not so well - including keeping cool instead of just reacting to problems.

"It's critical for families to seek support early, and not just wait until a problem becomes a crisis," says Sherwood. "Your teenager's behaviour might be frustrating, but they're facing a lot of challenges and you're still the adult in the relationship.

"Give them space when they need it, stay calm and remember that help is available."