How does my doctor know I have breast cancer

If you're having symptoms of breast cancer or have something suspicious that has shown up on a previous test, your doctor will want to follow up. Your doctor is likely to ask you questions about these things:

  • Your medical history
  • Your family history of cancer
  • Any exposure to other risk factors, such as high doses of radiation
In addition to asking questions, your doctor may also perform one or more of the following exams or tests:
  • Clinical breast exam
  • Mammography
  • Ultrasound

Each of these tests is described in detail below.

Clinical breast exam

Feeling your breast can help your doctor figure out the size and texture of any abnormalities. Noncancerous lumps, called benign lumps, often feel different from cancerous ones. First you will remove your clothes from the waist up. Then your doctor will look to see if your breasts have changed in any way, such as in shape or size. As you sit and lie down in different positions, the doctor will feel for any lumps. If your doctor feels a lump, you may need other tests, such as a mammogram or ultrasound.


Mammograms are quick and easy, though the test itself may be uncomfortable. You undress from the waist up, covering your upper body with a wrap provided by your doctor. Then you stand in front of an X-ray machine. Tell the staff if you have trouble standing so they can help make you more comfortable. A technician, usually a woman, will help position your breast on the X-ray plates. The plates squeeze together to flatten the breast so that the X-ray machine can get a clear picture of the breast tissue. The pressure of the plates may pinch a little, and the positioning of your body can be uncomfortable, but it usually lasts for only a few seconds. Tell the technician how you feel and she will help you find a position that is as comfortable as possible. The whole process lasts about 20 minutes.A mammogram is an X-ray of your breast. It can give the doctor important information about a breast lump. Some facilities use digital mammography, which also uses X-rays, but collects data on the computer, instead of on film. If something looks unusual, more mammograms or other tests may be needed.

You'll be more comfortable if you schedule your mammogram about a week after your period. Your breasts may be tender during menstruation and the time leading up to it, which can make the test more uncomfortable.

To make sure that you get the most reliable results, follow these tips:

  • Don't wear deodorant or body powder on the day of your mammogram. It can show up as dark spots on the X-rays and interfere with the radiologist's ability to check the condition of your breasts.
  • Stand perfectly still during the mammogram. If you move, the results might be blurry, and then you'll need to have those pictures taken again.
  • If you've had previous mammograms or biopsies at another facility, bring a list of the dates and locations where these were done. If possible, bring the actual mammograms themselves. It's a good idea to get these from your old facility if you decide to switch to a new one.
  • Choose your mammography facility with care. Your facility should have a prominently posted FDA certificate stating that it meets the required standards of safety and quality. If it doesn't, you have every right to ask to see it. If they don't have this certificate, go somewhere else. Try to have your mammograms at the same facility each year. The longer a facility does your screening, the more familiar they are with your records, and the more likely they are to catch any changes.

You should have the results within 10 days. If there's a problem, you'll hear from the doctor within 5 working days. If you don't hear anything, don't assume that no news is good news. Follow up.


An ultrasound uses sound waves to find out whether a lump is solid or filled with fluid (a cyst). This exam may be used along with mammography. During an ultrasound, your doctor or a technician spreads a thin coating of lubricating jelly over the area to be imaged. A hand-held device called a transducer directs the sound waves through your skin toward specific tissues. As the sound waves are reflected back from the breast tissues, the patterns formed by the waves create a two-dimensional image of the breast on a computer. The test doesn't take long and is painless.

How your doctor uses these test results

These exams may help your doctor decide whether or not you need any more tests or treatment. If any of these test results suggest that cancer may be present, your doctor may need to remove a small amount of breast tissue, usually with a needle. This is called a biopsy. A doctor will suggest doing a biopsy when something suspicious is found in one or more of the tests above.

If you've been seeing your primary care doctor for screening up until this point, your doctor may refer you to a surgeon or another doctor who has experience with breast diseases and biopsies to perform the procedure. A biopsy is the only way to definitively diagnose breast cancer.