CHICAGO (AP) _ Despite the laid-back image of the West, more women in that part of the country report feeling stressed, according to a new survey in which the majority of American women said they lead stressful lives.

Fifty-seven percent of all women questioned said they thought they led stressful lives, and more than one-third reported feeling chronic fatigue, according to the survey, commissioned by Miles Laboratories Inc. of Elkhart, Ind.

Nearly two-thirds, or 64 percent, of the women surveyed in the West said they were under a lot of stress. In contrast, 49 percent of the women in the Northeast reported high stress, the survey found.

The study, conducted in the first quarter of 1987, questioned 600 women ages 18 to 59 on their nutrition and health. Results of the survey, which had a margin of error of four percentage points, were released in Chicago last week.

Among Southern women, 61 percent reported stress, while 54 percent of the Midwestern women did.

''Northeastern women are used to living frenetic lives, with having to deal with a lot of tensions and pressures because that's the lifestyle in the East,'' said Abby Bloch, a nutritionist with the Memorial Sloan-Kettering Cancer Center in New York City and a member of the Within Women's Health Advisory Board sponsored by Miles.

''Women in the South and West haven't yet developed the coping methods that the women in the Northeast have,'' Ms. Bloch said in a telephone interview Monday night.

Broken down by age group, the number of women who said they felt high stress levels included 61 percent of those aged 35-44, 57 percent of those aged 18-34 and 54 percent of those aged 45-59.

''Working women have the equivalent of two full-time jobs. The feeling of needing to meet everyone's demands weighs very heavily,'' said Marigold Edwards, associate professor of health education at the University of Pittsburgh and a member of the Within advisory board.

High levels of stress have been linked to such problems as headaches, sleep disorders and depression, Ms. Edwards said.

The survey also found that younger women are more likely to suffer from chronic fatigue than older women.

''These older women handling careers and family have a more routine or stable life than younger women, so they have some constancy and can do their work easier and with less fatigue,'' Ms. Bloch said.

Ms. Bloch said the survey also indicated many women have misconceptions about nutrition, citing survey results that indicated 72 percent of women believed vitamins could prevent everyday illnesses.

''A lot of women think, 'I'm stressed and not eating well, so I'm going to take high-potency multivitamins, and it'll fix me up,''' Ms. Bloch siad. ''That's not the solution to their stress.''