Lyndsay Baldwin had been arguing with her mother for years. Lyndsay’s parents were divorced, and she found herself caught in the crossfire. When she went to stay with her dad, her mother saw it as a betrayal. When she returned to her mother’s, her dad took offence. Her dad subsequently severed all contact, moving house and leaving no forwarding details.

Then, a few weeks before Lyndsay turned 16, her mother announced that she wanted her out of the house. The day before her birthday, Lyndsay found her bags packed, her mother delivering on the threat.

“I didn’t believe it,” she says now. “You don’t believe your mum would do it.”

With one parent missing and the other having rejected her, Lyndsay had nowhere to go. Three months before her GCSEs, she was homeless.

More than 90,000 children and teenagers in England are living in temporary or makeshift accommodation. Some, like Lyndsay, have been driven out of home by a failing relationship with a parent or step-parent. Others are thrown onto the street by parents thinking this might scare them into giving up a damaging drug habit. The majority then drop out of school, college or work, eventually ending up on the streets.

But a significant number continue going to school, clinging desperately to the last shreds of a normal life. And, says Gill Richmond-Burns, of the homeless charity Shelter, such pupils can be much harder to spot than anticipated.

Indeed, it can be particularly difficult to identify homeless pupils when, often, they do not even see themselves as homeless. When Lyndsay’s mother threw her out of home, for example, she went to live with her boyfriend.

“They’re sofa-surfing, staying with friends,” Ms Richmond-Burns says. “It feels like an extended holiday. They don’t feel that they’re homeless, because they have a roof over their heads. But the roof isn’t theirs.”

This became clear to Lyndsay when she broke up with her boyfriend within a few weeks, and was immediately forced to find somewhere else to live. This time, she moved in with her older brother, who helped her identify and claim the benefits that were available to her. However, he had other priorities: his own daughter was ill with cancer.

“He had to take her for treatments,” Lyndsay says. “He didn’t have room or time for me, with everything that was going on. So I stayed with friends, but they couldn’t keep me, because of their parents. So I was just going from house to house.”

“You would be amazed how many people sofa-surf,” says Claire Mould, executive director of Five Valleys Foyer hostel for young adults, in the Gloucestershire town of Stroud. “Most spend a week in one place, then move on somewhere else for another week. They don’t want to arouse suspicion with their friends’ parents.”

In fact, these fears are often ungrounded. Ms Richmond-Burns conducts homelessness-awareness workshops in schools, and is repeatedly astonished by the level of wilful blindness among teachers. “They feel that homelessness isn’t something that is going to happen to the children in their schools,” she says. “And you think, `Oh, dear. Wise up.’ It’s not exclusive to schools in more disadvantaged areas. It can happen across the board.”

Five Valleys Foyer, for example, worked with one girl, from a family Dr Mould describes as “incredibly middle-class”. Her parents were Jehovah’s Witnesses, but at the age of 13 the girl decided that she had no interest in the religion. Her parents responded by throwing her out of home. For a while, she sofa-surfed at friends’ houses, but eventually ended up sheltering overnight at bus stops.

“She was an incredibly intelligent young woman,” Dr Mould says. “To be able to survive on your own on the streets when you’re 14 or 15 is no mean feat. If she hadn’t been thrown out of home, she would be a university student now, without a shadow of a doubt.”

Lyndsay, however, had no intention of allowing her homelessness to disrupt her education. “I wanted to get my GCSEs,” she says. “I’d been working really hard at them, so I wanted to keep going to school.” She confided only in her English teacher: “She listened to everybody, didn’t judge people. I always got on with her.” Insisting to the teacher that she was safe, she begged her to keep the information to herself. All she wanted, she said, was to be able to use the school library after hours.

In fact, her decision to tell even one teacher was unusual. Homeless teenagers are often reluctant to admit to their situation to anyone at all. “It can be quite an embarrassing thing,” says Dr Mould.

“Would you confide in your mate that your stepdad had kicked you out? Or that your own parent has chosen someone else over you? Either way, it doesn’t look good. You can’t help but take it personally. So you would be more likely just to say, `Oh, can I stay here for a night, because my mum’s doing my head in?’”

Jamie Keast was days from his 16th birthday when he and his father had the latest - and worst - in a long line of arguments, stretching back through his teenage years. “He was asking me to do too much,” says Jamie. “He was just getting to me. So I just packed my bags and went.” He was already on study leave for his GCSEs - the exams were less than a month away.

Sleeping on the sofa of a friend’s flat, he was embarrassed to tell anyone else exactly what had happened. “I thought it were my fault,” the Rotherham teenager says. “When people were saying that they wanted to come to mine, I kept it quiet for as long as I could. I didn’t want anyone to know.”

Lyndsay, too, felt that her situation was her own fault. No longer able to stay with her brother, she was living in a caravan in a friend’s garden while she waited for a place to become available at a local hostel. “It’s actually quite embarrassing,” she says.

“I was worried everyone at school would find out and that they would judge me for it. People judge homeless people. They think they’re dirty, or on drugs, or alcoholics. They think that every homeless person is basically a skank.”

Fear of being judged, however, was not her only problem. She had been kicked out of home in February; the hostel would not have a place until August. “It was really cold in the caravan,” she says. “I got a lot of colds at that time. I wasn’t sleeping that well.” With no experience of looking after herself, she was surviving on Pot Noodles and pre-packaged sandwiches: “I was constantly feeling not that good,” she says. “I didn’t want to do nothing, to speak to anyone. I was feeling depressed.”

The sudden transition from home-dwelling, parent-relying teenager to independent adult can be a chastening one. “It’s amazing the number of pupils who think that the first thing they will do when they’re 16 is leave school. Then the next thing they will do is leave home,” says Ms Richmond-Burns. “But they have no plan or structure - they haven’t much idea how they expect to live. A lot of people think you can just go to the council and ask for a flat. Reality comes as a bit of a shock.”

This was true for Craig Johnson. His mother remarried when he was four years old; his fights with his stepfather began not long afterwards. As he grew older, the arguments became increasingly vitriolic, his stepfather increasingly aggressive. The day Craig turned 16, his father said, “There’s the door”, and told him to leave.

Suspecting that this day might come, he had already scoped out alternative living options, and moved straight into Five Valleys Foyer. It was July, and he had completed his GCSEs and signed up for A-levels at his local sixth-form college. Five Valleys Foyer staff helped him to claim housing benefits and income support: this came to a total of pound;40 a week.

“My stepdad was very strict - put a foot wrong and I got in trouble,” Craig says. “So I was very controlled. And then suddenly I had to support myself. I’m not going to lie - I struggled a lot.

“At the time, I was smoking quite a lot of cannabis. Buying that, and food for the munchies, it was quite difficult. You can’t go to the pub. You can’t go out and make new friends. I was living on pasta and beans and bread.

“And I wasn’t used to getting myself up, so I wasn’t getting into college on time, was oversleeping. I could do anything I wanted, and I ended up going off the rails completely. I pretty much dropped my A-level subjects one by one.”

A teacher at college approached him to discuss his persistent lateness. After the conversation, Craig decided to drop two of his A-levels, maths and psychology, and take up media studies instead: “I thought it would be more enjoyable, so that would give me motivation to get in and do it.”

Staff at the hostel allowed him to do his homework in their offices, but he ran into other problems. “At the weekend my social circle took over, if you know what I mean,” he says.

Such peer pressure is not unusual, according to Annabel Hallam, young persons’ housing adviser for Shelter. “Sometimes teenagers are worried that, if they do homework in the hostel, they will be seen as outcasts,” she says. “They can be bullied because they’re not going out and getting drunk. They’re getting bulled because they’re doing something to get on with their education.”

The college made no effort to find out why Craig was falling behind with his work. “No one said, `How are things going?’” he says. “It was pretty much, `You’re struggling, and you need to buckle up or you’re going to get kicked out’.” By the end of the year, he had dropped every subject apart from theatre studies. He received an E grade at AS level, not enough to continue to A-level. And so he left college and found a job as a sales assistant at WHSmith.

Jamie, too, found it impossible to concentrate on his upcoming GCSEs while negotiating a place to live. “I got all rubbish grades,” he says of his one D and seven sub-D results. “It was just too much all at once. The smallest things wound me up. But at least I sat them.”

He spent the summer after his GCSEs working in a warehouse, before eventually signing up for a course in mechanics. But, already paying pound;30 a fortnight for food and board, he could not afford the bus fare to college, and had to turn to a friend for a loan. “I was pretty skint then,” he says. “To be honest, I just wanted to try and get a job.”

Lyndsay succumbed increasingly to depression. She made it through her GCSEs, achieving five A-C grades, as well as two more passes. But the effort had taken its toll. “I was just completely drained,” she says. “From being a normal, happy person, I’d gone to being skinny, white, drained. I wasn’t the same person. And that’s when people started to notice.”

Eventually, inevitably, Dr Mould says, it will become apparent that homeless teenagers are having problems. “The easiest thing to spot is skin tone,” she says. “They’ll be quite grey, quite spotty, quite ashen-like. Their appearance is just a little bit off, a little bit ragged around the edges, as if they’ve just got out of bed and turned up to school.”

here is often a change of attitude, as well. Homeless teenagers will either become sullen and withdrawn or rebellious and defensive. Previously well-behaved pupils will start answering back in class, becoming increasingly aggressive.

“Look into their eyes,” Dr Mould says. “You can tell an awful lot by looking into individuals’ eyes. There is generally a lost look - you can tell it’s about more than being an aggressive young man or woman. There is a little bit of an edge to it.”

More and more, Lyndsay’s friends and teachers began to approach her, expressing concern. “Are you feeling OK?” they would say. “Would you like to go home?” Lyndsay responded by bursting into tears. “They were all telling me to go home,” she says. “But I didn’t have a home to go to.” By the end of term, she suffered a full-scale nervous breakdown.

“You can feel completely isolated,” says Ms Richmond-Burns. To guard against such outcomes, she believes that schools should highlight the perils of homelessness from the beginning of secondary school onwards. Her Rotherham scheme, funded by Barclays Bank, brings formerly homeless young people into schools to talk to pupils about their experiences. “Children need to know what to do,” she says. “They think if they’re sleeping on someone’s sofa, that’s OK. But it isn’t. Teachers should be hammering home that message: `If you find yourself in that situation, come and see us. This is what we can do.’”

Lyndsay’s English teacher, although a good listener, was out of her depth. Beyond compiling a list of useful telephone numbers, she had no idea what to do. It was, in fact, one of Lyndsay’s friends who arranged for her to see a counsellor.

The August that her GCSE results came out, she secured her place at the hostel; its staff helped ensure she was on the priority list for a council flat. They also offered regular cooking lessons. She can now cook lasagne, chicken and spaghetti bolognese. She bakes and freezes pies, to see her through intense revision periods.

On her 17th birthday, she was given her own council flat. She is now taking a college course in social care. Her aim is either to work as a carer for the elderly, or to become a nurse. “I’d like to go to university,” she says. “It would be difficult, but if you don’t try, you don’t know. Now I’m a lot more confident in what I do. I’ve got the things I need, I’m eating properly, I’m feeling better in myself.

“Living on your own is a bit lonely. But it proves you can do things and don’t need people around you. I feel a lot more mature than people in college - what I’m doing now, they’ll be doing in four, five years’ time. It gives you a lot of independence.”

She has been relatively lucky. It is only now, three years after being made homeless, that Jamie feels in control of his life once more. It took two years for him to find a council flat and begin to pay back his debts.

Craig had five years of false starts, thwarted ambitions and failed relationships, before he was finally able to settle in a council flat. He now works as a support worker for young residents at Five Valleys Foyer, offering advice from his own experience.

“Really, you’re doing an A-level in life,” he says. “You’re going from living at home, having food on the table, everything supplied for you, to being completely independent, having to look after yourself. That was harder than the academic stuff. It’s sink or swim with life, isn’t it?”

A teachers’ resource pack is available at: www.shelter.org.uk.

Original headline: `People think you’re basically a skank’