Nicole Chapman, Headteacher of Chelmsford County High School for Girls, says it was noticeably tougher for her students to achieve top marks this year.
She also voiced concerns about the costs of university faced by some students.
Thousands of students who do not get the results they hoped for still get places at university through clearing. Here's how it works.
Universities across the East of England are dealing with thousands of calls from students trying to find places.