Bias arises sometimes because men have been used as the normative standard in medical research. So a complaint by a woman may be unrecognized due to different symptoms, or may be untreated or treated inappropriately. Many ailments, especially attendant on older women, receive if not unequal treatment, unequal attention. There is also a pervading attitude of many physicians about women's complaints that can lead to misdiagnosis where the woman is perceived as suffering from a psychological rather than physical problem. While the medical profession remains male-dominated, a gender slant in inevitable.
Bernadine Healy, a cardiologist and the director of the USA National Institute of Health, called the presumably inadvertent sex bias the "Yentl syndrome" – after the famous I.B. Singer story. Just as the girl, Yentl, had to masquerade as a man to get an education, so a woman has to experience a full-scale heart attack like a man before she can get equal treatment.
Two recent studies showed that doctors treated women with heart disease less aggressively than they treated men – even though in the women the disease tended to be further advanced. The women were half as likely to undergo cardiac catheterization and much less likely to have bypass surgery or a procedure to unclog blocked arteries. There is also very little good information on treated hypertension in women. A recent review of several major studies found that treatments that work for men may be ineffective or even harmful for white (though not black) women. Women seem to suffer from clinical depression more often than men, but the research on anti-depressants was initially done only with men. Now there is evidence that the effects of some anti-depressants vary during the menstrual cycle, which means that a dosage can be too high at some times and too low at others. Osteoporosis, 90% of whose suffers are women, and general frailty of the elderly are other poorly researched areas.