The Berlin questionnaire mainly evaluates sleep-disordered breathing (obstructive sleep apnea), but also assess waketime sleepiness or fatigue and the presence of obesity or arterial hypertension. It consists of 10 questions, divided in three categories. The first five questions are included into category 1, questions from six to eight into category 2, and question 10 in category 3 (question nine is evaluated separately). A positive response to two questions of the first 2 categories, or to the single question of category 3, marks the corresponding category as "positive", and positivity of two or more categories classifies the person as at "high risk" for having obstructive sleep apnea.