In an unfamiliar environment where people speak different languages, communication is a huge challenge.
The only Chinese student among 150 junior students at a private college in Oxford, Junfei, 16, was sent to study in Britain at the age of 12.
Junfei said he constantly felt anxious, lonely and alienated.
When he first arrived at Oxford, he refused to step out of his room and cried for three days.
"I was scared, everything was so unfamiliar," Junfei said.
Gao Qin, Junfei's aunt and guardian, said the boy felt overwhelmed.
"The language barrier was a burden. He couldn't socialize or have any friends at the beginning," Gao said.
Junfei said: "I once got into a fight because I thought another student was teasing me. The school was about to expel me. They thought I was a troublemaker."
Zhang Xinwei, a child psychologist in Wuhan, Hubei province, agreed that challenges faced by young students in a foreign environment can cause problems.
"Academic stress and separation from parents both aggravate adolescents' anxiety," Zhang added.
In the UK, any student under the age of 16 must have a legal guardian.
Parents who don't have friends or relatives living in the UK normally turn to local guardianship agencies.
Most agencies provide counseling services and help to contact host families and local coordinators. Bright World, a guardianship company in West Sussex, charges fees per term for a package of services, including school admission support, 24-hour emergency calls and two visits per term.
Richard Purchase, director of Abbey DLD Colleges, said the London College has 440 students from 39 different nationalities and 16 percent of the students come from China.
The colleges also have campuses in other UK cities, and at Abbey College Cambridge, 50 percent of the students are from China.
Childhood in an isolated sterile room