If you have these red flag signs or symptoms, you'll need additional testing to further assess your condition.

CNN: Irritable bowel syndrome

Other suspicious chemical discoveries in Iraq since the beginning of the war have, after additional testing, turned out to be pesticides or other industrial chemicals.

CNN: Initial tests of Iraqi chemicals show nerve agent

But the NUT said candidates who needed several resits to pass the tests were dyslexic, had English as an additional language, or were less familiar with the on-line testing system.

BBC: Literacy and numeracy tests toughened for new teachers