ATLANTA , Georgia ( CNN ) -- A paper cape sits loosely around your shoulders , covering your naked chest . A radiology technologist directs you toward an imposing-looking machine . As you hold your breath , one bare breast at a time is tightly compressed between two flat panels and X-rayed . You 'll undress from the waist up for a mammogram ; wearing two pieces , not a dress , makes it easier . It 's a scene that 's been repeated more than 35 million times in the past year at certified mammogram facilities around the United States . No matter what their age , race or medical history , the female patients probably shared a similar experience during the 20-minute procedure . `` Mammograms are known to be uncomfortable , '' concedes Dr. Sujatha Reddy , an Atlanta , Georgia , -based gynecologist . `` The harder they squeeze and squish that breast , the less tissue the X-rays have to go through and the more likely they are to find something . '' The American Cancer Society reports two to four mammograms out of every 1,000 lead to a diagnosis of cancer . About 10 percent of women who have a mammogram will require more tests . Accuracy often depends on patient cooperation , but Reddy reveals there 's another side as well : `` A mammogram is only going to be as good as the technician and the doctor who read it , so you want to go to a good place . '' A recent study in the Journal of the National Cancer Institute reports that doctors reading mammograms miss an average of two in every 10 cases of breast cancer . Medical experts remind women that mammograms alone do n't guarantee a clean bill of health . `` I wish I could say the mammogram could find 100 percent of breast cancers , '' Reddy said . `` I think we have to rely on having a clinical breast exam once a year at a health care provider and doing your self-breast exam on a monthly basis . '' Reddy recommends having mammogram screenings at a reputable facility that is certified . She also suggests going to the same office every year so that old X-rays can be compared with new films . A convenient location is another factor that makes it more likely that someone will actually show up for an annual mammogram appointment . Health Minute : Watch more on what to expect during a mammogram . » . Fear of discomfort is what often keeps some women away . Reddy advises her patients to schedule a screening appointment for the early part of their menstrual cycle . `` The best time of your cycle to do a mammogram is going to be when your period is over , maybe the week after your period is done when the breasts are not going to be tender . '' Caffeinated coffee , tea and soft drinks may also contribute to tender , lumpy breasts . Experts recommend avoiding caffeine for a week before the procedure . Before having any type of imaging test , the Cancer Society warns patients to tell technicians if they think they might be pregnant or are breast feeding . Similarly , reveal any unusual breast symptoms or problems before a mammogram . The screening requires women to undress from the waist up . You 'll be given a disposable wrap to put around your shoulders and chest . Wearing a two-piece outfit will make the process easier and more convenient . Technicians tell patients not to wear deodorant , antiperspirants , perfumes or powders . They might leave a residue that can be picked up on the X-rays , interfering with the results . All mammogram facilities are required to issue results within 30 days , but many will contact patients within a week if there is a problem with the mammogram . The Cancer Society recommends women 40 and older get a mammogram every year . Younger women may be advised to be screened earlier if there is a family history of breast cancer . E-mail to a friend . Judy Fortin is a correspondent with CNN Medical News . CNN medical producer Linda Saether contributed to this report .
More than 35 million mammograms performed annually in the U.S. Be screened at the same place every year ; makes comparing images easier . Minimize discomfort by going early in your monthly cycle .