Parents often bemoan the transformation that takes place in their children during the teenage years, but for teachers coping with a whole class full of adolescents, things can be especially challenging.

Research is now uncovering some interesting facts about the physical and emotional changes plaguing the young during adolescence, and there are many websites offering sound advice. Teachers trying to understand the problems facing young people in their care can use the resources outlined here to gain greater insight into adolescence, and to pick up some helpful tips.Physical changes Some of the behaviour we associate with teenagers, such as mood swings, challenging behaviour and getting up late, may have physical origins. Scientists have discovered that the brain carries on growing well into the teenage years, and that the emotional centres develop ahead of the areas devoted to rational thought. This could account for the risk-taking behaviour of teenagers.

In addition, their rapid hormonal fluctuations could explain sudden mood swings, irritability, aggression and depression.Moreover, teenagers have been found to have less of the hormone melatonin in their bodies than adults at certain times of night. Since this hormone helps us fall asleep, it could be that young people's bodies are actually keeping them awake at those times, with subsequent problems in the morning. Rapid growth spurts during puberty can also explain some of the clumsiness found in teenagers, since the body simply grows too fast for the brain to keep up.

The BBC Science and Nature website Teenage Transitions has extensive information on some physical and behavioural changes affecting teenagers, and what might account for them.There are articles on everything from spots to voice-breaking, as well as explanations of emotional changes such as mood swings, sexual attraction, rows and rebellion. * Teenage Transitions The following are specific issues of concern in teenage health: * Sexual health and teenage pregnancy: The Teenage Pregnancy Unit is the starting point for information on teenage pregnancy, while further information on sexual health is available from Brook. * Eczema and asthma: Teachers magazine contains a useful article on the increase in asthma in young people.BBC Health has information on the causes and management of eczema. * Acne: Spots are one of the blights of teenage life.

Find out more about them on the BBC 'Human Body' feature 'Evil zits', Radio 1's body image advice for young people and the BBC Health feature 'Acne — get shot of spots'. * Nutrition: Learn more about what teenagers need to eat through the BBC's nutrition advice and the Wired for Health project, run jointly by the National Health Service (NHS) and the DCSF. The NHS also has a useful site, Teenager Health with links relating to many different aspects of the subject.Challenging behaviour As well as these physical changes, adolescents are struggling to cope with a developing sense of their own identity. They have to learn to become independent and to distance themselves from parents and family, at the same time as conforming to peer pressure and the need to be accepted by other young people. Add the stress of exams and developing sexual awareness into the equation, and it's obvious that adolescence is a very challenging time.

Unfortunately, teachers and parents are often on the receiving end of this confusion.Teachers magazine has a useful checklist for dealing with difficult behaviour, based on Sue Cowley's book, Getting the Buggers to Behave 2. TeacherNet's case studies include studies of how schools have dealt with issues relating to emotional health and well-being, such as responsible behaviour and bullying. There is an extensive list of resources devoted to positive discipline and improving behaviour on the End All Corporal Punishment of Children site, including links to information from UNICEF, Save the Children and the NSPCC.

Some parenting websites contain information that teachers might also find useful. BBC parenting has interesting tips on talking to teenagers as well as sections on academic pressure, bullying, discipline, thrill seeking, peer pressure, stress and sexuality. Raising Kids and Parentline Plus also explore a range of teenage issues, including the secret life of teenagers, truancy, relationships and drugs. Social and emotional well-being A teachers' page on emotional health and well-being appears on Mind, Body and Soul with activities aimed at helping teenagers with turbulent times in their lives.

The CHIPS campaign, run by Childline in schools, aims to help children to support each other and to communicate better. BBC Health's Links section offers helpful links to organisations devoted to improving confidence and self-esteem. Mental health can be a major concern for some teenagers. Young Minds aims to improve children's mental health and has booklets for young people who are developing into adults, while Papyrus helps young people contemplating suicide or in distress.

Teenage issuesA number of problems are frequently associated with teenagers, and may give teachers particular concern — fortunately though, a wealth of resources is devoted to these specific questions. The DCSF PSHE site is a useful starting point for some of the issues. Problems often encountered may include: * Substance abuse, such as drugs, alcohol and smoking: Teachers magazine has examples of how some schools are starting young with drugs education. BBC Parenting's article on Risky behaviour, BBC Health's drug use section and Healthy Schools have some tips on dealing with alcohol, drug misuse and smoking.The FRANK website outlines different types of drugs and the legal situation relating to them, whilst Mind Body and Soul gives examples of activities that teachers can use for talking about smoking in PSHE or science lessons. * Eating disorders: BBC Health has a useful article for Eating Disorders Awareness Week including links to organisations dealing with eating disorders, and some useful facts and figures.

* Self-harm: TeacherNet has an article on Self-harm and its effect on young people. BBC Gloucestershire's article 'Drawing attention to a hidden affliction' examines the case of a young woman who began to self-harm. Exam stress: Teachers can help teenagers cope with exam stress by giving them tips on revision and by encouraging positive thinking. TeacherNet's article 'Revision Help' tells you how. * Bullying: There's lots of useful advice on coping with bullying, for both teachers and young people, at Bullying Online. Dealing with life's problems Certain difficult events may not be particularly associated with teenagers — but it's still helpful to understand the particular ways in which teenagers may react to them.

Online resources may be helpful in understanding young people's feelings about important life events, and in developing a strategy to help them. * Bereavement: The Childhood Bereavement Network can advise teachers on how to help young people who have been bereaved. There's also a checklist of how children may react at the BBC's How bereavement affects children site and a site for young people at RD4U. * Epilepsy: Epilepsy Action is a friendly and informative site for young people with epilepsy.

* Divorce: Divorce can affect young people's behaviour in school. Find out more about this subject at Divorce Aid.