context: Mammography uses special X-ray images to detect abnormal growths or changes in the breast tissue. Using a digital X-ray machine made especially for breast tissue, a technician compresses the breast and takes pictures from at least two different angles, creating a set of images for each of your breasts. This set of images is called a mammogram. Breast tissue appears white and opaque and fatty tissue appears darker and translucent. In a screening mammogram, the breast is X-rayed from top to bottom and from side to side. A diagnostic mammogram focuses in on a particular lump or area of abnormal tissue. Mammograms are performed as part of a regular physical exam to provide a baseline reference for future comparison or to evaluate any unusual changes in the breast. A mammogram can help your health care provider decide if a lump, growth, or change in your breast needs further testing. The mammogram is also used to look for lumps that are too small to be felt during a physical exam. Mammography can be your best defense against breast cancer because it can frequently detect the disease in its early stages, often before it can be felt during a breast exam. Research has clearly shown that mammography can increase breast cancer survival. Inform your doctor or the technician performing the test if you are pregnant or think that you may be pregnant. No dietary changes are necessary. Take your medicines as usual. Do not wear body powder, cream, deodorant, or lotion on your chest the day of the test. These substances may interfere with the X-rays. At the time of the mammogram, you will be asked to remove all clothing above the waist and you will be given a hospital gown to wear. You may want to wear a two-piece outfit the day of the test. You will be asked to remove all jewelry. Registered mammography technologists perform the test. Most mammography technologists are women. A doctor specialized in interpreting imaging studies (radiologist) will interpret the X-rays. You will be asked to stand in front of an X-ray machine. The mammography technologist will place your breast between two radiographic breast supports. The supports will be pressed together, gently flattening the breast. Compression is necessary to obtain the clearest possible picture with the least amount of radiation. You may feel some discomfort or slight pain from this pressure, but it will only last for a few seconds while the X-ray is being taken. Your cooperation for these few seconds is important to get a clear picture. If you feel that the pressure on your breast is too great, tell the technologist performing the exam. To minimize discomfort during compression, you may want to consider scheduling your appointment seven to 10 days after the start of your period, when your breast are least likely to be tender. The breast will be imaged in several positions to enable the radiologist to see all breast tissue adequately. For a routine breast screening, two pictures are taken of each breast. This exam takes about 20 minutes. Many centers also do 3- D mammography. This is similar to regular mammograms but many more pictures of the breast are taken at various angles to produce a 3- D picture for the radiologist to check. After examining the digital images, the radiologist may ask the technologist to obtain additional images or a breast ultrasound for a more precise diagnosis. This is a routine measure. After a mammogram, you may experience temporary skin discoloration or mild aching as a result of the compression in the breast area. You may take aspirin or ibuprofen to relieve the discomfort. Generally, you will be able to resume your usual activities immediately. The results of your mammogram will be given to your doctor, who will discuss with you what the test results could mean and what further tests might be recommended. All mammography facilities are now required to send your results by mail to you within 30 days. You will be contacted within five working days if there is a problem with your mammogram. If you do not hear about your test findings within 10 working days, don't assume your results are normal -- call your doctor to make sure. According to the American Cancer Society, approximately one to two mammograms out of every 1,000 lead to a diagnosis of cancer. Approximately 10% of women will require additional mammography. Don't be alarmed if this happens to you. Only 8% to 10% of those women will need a biopsy, and 80% of those biopsies won't be cancer. Those odds may improve with more widespread use of three-dimensional mammography. Your risk of breast cancer increases as you age. But there's disagreement among breast cancer experts regarding when you should have your first mammogram. The American Cancer Society recommends women ages 40 to 44 should have a choice to start yearly screening mammograms if they would like. Women ages 45 to 54 should have a mammogram each year and those 55 years and over should continue getting mammograms every 1 to 2 years.. Experts disagree on when to start getting mammograms, so you should discuss this with your doctor. The U. S. Preventive Services Task Force recommends screening every 2 years from ages 50 through 74 and that the decision to start yearly screening mammograms before age 50 should be an individual one. Whether you need a mammogram is a personal decision between you and your doctor. If you're over age 40, talk to you doctor about when you should begin mammogram screening. Mammograms are an important part of your health history. If you go to another health care provider or move, take the film (mammogram) with you. Not all breast cancers can be detected on mammogram, especially in younger women who have denser breast tissue. You may also have breast exams done by your health care provider (physician or nurse) every three years starting at age 20 and every year starting at age 40.