Men and women have different nightmares.

PhysOrg divides bad dreams between the sleeping sexes:

The study, carried out by Dr Michael Schredl of the International Association for the Study of Dreams, involved over 2,000 people, who were asked to report on their bad dreams.

The study found nightmares about being fired from a job, or about violence were more common in men, while for women nightmares of sexual harassment or a death of a loved one were more prevalent. Women were also more likely to have bad dreams about losing their hair or teeth, perhaps suggesting an anxiety about becoming unattractive. Both genders reported nightmares about failing exams, and they could have such dreams even if they were not students.