Breast Cancer Screening and Diagnosis

Written by Kim Painter
Medically Reviewed by Zilpah Sheikh, MD on May 08, 2025
8 min read

The sooner breast cancer gets diagnosed, the better your odds of getting successful treatment.

So, it’s important to get mammograms as recommended, know how your breasts usually look, and report any changes to your doctor ASAP. 

Breast cancer risk is up now. The lifetime risk of a woman getting breast cancer in the U.S. was around 5%, or 1 in 20, in 1940. Now it’s 13%, or more than 1 in 8. But thanks partly to early detection, breast cancer deaths are declining. Screening “saves a lot of lives,” says Ethan Cohen, MD, a radiologist who is an associate professor at The University of Texas MD Anderson Cancer Center, Houston.

Women and people assigned female at birth (AFAB) who have regular breast cancer screening mammograms are not just less likely to die from the disease, but also less likely to need aggressive treatment. This depends on:

  • The quality of the test
  • Getting screened as often as you need to
  • Following your treatment plan if you get diagnosed

Self-exams

It’s a good idea to know how your breasts normally look and feel so you can notice any changes. You can do this by regularly looking at your breasts from all angles in a mirror and using your fingers or hands to feel them. Some people use soapy hands in the shower.

Most medical organizations no longer recommend self-exams as a formal breast cancer screening tool. The American Cancer Society, for example, says research has not shown a clear benefit of doing regular breast self-exams. Talk with your doctor to better understand what’s right for you.

Learn more about how to do a breast self-exam.

Clinical breast exams

A clinical breast exam is done by your doctor, to feel for lumps or other changes. It might be done as part of your regular checkup. But not all doctors’ groups recommend it for people at average risk of breast cancer. Your doctor might be more likely to offer it if you’re at higher risk. 

When you get a clinical exam, your doctor will feel both your breasts, one at a time. They’ll also check the underarm and collarbone areas. If they notice suspicious lumps, they may ask you to get other tests. Your doctor will also examine the breasts visually for any rashes or anything else that looks unusual. And they may lightly squeeze your nipples to see if any fluid comes out.

Mammograms

A mammogram is an X-ray of the breast. It can show breast lumps up to two years before they can be felt. Different tests help determine if a lump may be cancerous. Ones that aren’t cancerous tend to have different physical features than ones that are. Imaging tests such as mammograms, MRIs, and ultrasounds can often show the difference.

Screening mammograms are used to look at your breasts when you don’t have a specific lump or other concern.

Diagnostic mammograms focus on a specific area or areas of your breasts that you or your doctor is concerned about, such as where you have a suspicious lump, pain, discharge from a nipple, changes in size or shape, or certain skin changes.

When and how often you need screening mammograms is a personal decision you should make after discussing with your doctor. Most women and people assigned female at birth don’t start having screening mammograms until they’re at least 40. If you’re at higher risk for breast cancer, your doctor may want you to start at a younger age.

Breast MRI

This test combines several images of your breast into one to create a detailed picture. It’s not normally used as a screening test if you’re at average risk of breast cancer. But your doctor might combine it with a mammogram as a screening test if you are at higher risk because:

  • You have a family history of breast or ovarian cancer.
  • Your breasts are dense (there are a lot of ducts, glands, and fibrous tissue, but little fat) and mammograms didn’t find a previous breast cancer.
  • You have dense breasts, a strong family history of breast cancer, and had precancerous breast changes, such as atypical hyperplasia or lobular carcinoma in situ.
  • You have the BRCA1 or BRCA2 gene mutation.
  • You had radiation treatments to your chest area before you were 30.

Breast ultrasound

Your doctor is most likely to use this, in addition to a mammogram, if you have dense breasts. It’s also an option if you’re at high risk for breast cancer and you can’t have an MRI or if you’re pregnant and need to avoid X-rays from a mammogram. While ultrasound is more widely used and less expensive than MRI, it has not proven to be as effective for added screening as an MRI, Cohen says.

Thermography

This test uses an infrared camera to find temperature differences in your breast tissue. The idea is that “hot spots” show inflamed areas that could be cancer. 

But the FDA says thermography hasn’t been shown effective as a stand-alone screening test for detecting early breast cancers. It’s not a replacement for a mammogram and should only be used along with reliable screening tools such as mammography, the FDA says. 

Leading medical groups, such as American Cancer Society, the American College of Radiology, and the Society of Breast Imaging, don’t recommend thermography for breast cancer screening. And many insurers won’t pay for it.

As with any medical screening test, mammograms and other tests to detect breast cancer early carry some risks. These can include:

False positive results. Most abnormalities found on screening mammograms turn out not to be cancer. But you’ll need extra tests to find out. Waiting for final results can cause a lot of anxiety.

False negative results. The tests might miss a cancer and create false reassurance. For example, if you find a lump soon after receiving a normal mammogram result, you might not call your doctor — though you should. 

Unneeded treatment. Some breast cancers found by screening would never advance enough to cause health problems or shorten your life. So getting treatments such as surgery, radiation, or chemotherapy would expose you to unneeded risks and side effects.

Pain or discomfort. Some people find mammograms painful because during the test, the breast is squeezed firmly between two plates. Taking over-the-counter painkillers, such as ibuprofen or acetaminophen, may help.

Radiation exposure. Because a mammogram is an X-ray, it uses radiation. While high doses of radiation increase cancer risk, the levels used in mammography are “very, very, very minimal,” Cohen says.

Expert groups who’ve weighed all the potential benefits, as well as the risks, offer varying advice about when and how often you should get a screening mammogram and any additional tests. But they generally recommend starting sometime between ages 40 and 45 for women at average risk. 

Specifically, for women at average risk, the American Cancer Society recommends that women aged:

  • 40-44:May decide to start yearly mammograms
  • 45-54: Should get yearly mammograms
  • 55 or older: Can switch to getting a mammogram every other year or continue getting yearly mammograms

The U.S. Preventive Services Task Force (USPSTF) recommends screening mammograms every other year for women of ages 40-74. 

The American College of Radiology and some other doctors’ groups recommend mammograms every year starting at the age of 40. That saves the most lives, outweighing any added risks or costs, in the view of those groups, Cohen says.

The radiology group also says every woman or a person AFAB should talk to their doctor about their personal risk for breast cancer, starting at age 25, to see whether earlier screening makes sense. It’s especially important for Black and Ashkenazi Jewish women, who may have higher genetic risks. Black women are also more likely than White women to get advanced breast cancer and die from it before age 50.

Other screening tests, such as MRIs, may be recommended if you have dense breasts or other risk factors.

If your breast cancer screening turns up a mass or other signs of breast cancer, you’ll need additional tests to find out if you actually have cancer and what it may mean for your health.

The only sure way to confirm cancer is a biopsy. Your doctor may use a needle or, less commonly, do surgery to get a sample of tissue from your breast. The sample can be tested for cancer cells.

Find out what to expect with a breast biopsy.

If you’re diagnosed with breast cancer, you and your doctor will need to know what type it is and how advanced it is. A check of your lymph nodes can tell whether the disease has spread. Other tests give an idea of which treatments may work best for you, and still others predict how likely it is that your cancer will come back after treatment.

Your doctor can help you understand all of these tests, and together you’ll decide on the best treatment plan for you.

Get more information on what to do after a breast cancer diagnosis.

Breast cancer screening can help you find breast cancer early, when it’s most treatable and potentially curable, lowering the risk of death from breast cancer. While screening recommendations might seem complex, the overall message is simple: Talk to your doctor about your breast cancer risks, then decide on a screening schedule, and stick to it. 

Do men and people assigned male at birth (AMAB) need breast cancer screening?

Anyone can get breast cancer, but men are at much lower risk than women. Doctors don’t generally suggest men get screened. Men and people AMAB — including those who are nonbinary or transgender — may be at somewhat higher risk if they take estrogen. Some doctors’ groups recommend breast cancer screening in that situation. In any case, if you are at high risk because of a strong family history or gene mutations, talk to your doctor about watching for early signs of breast cancer. Anyone who finds a breast lump or other breast changes should get it checked out.

At what age should breast cancer screening be discontinued?

This is still an open question and a good topic to bring up with your doctor. The American Cancer Society and American College of Radiology say women should keep getting screened for as long as they are healthy, though the cancer society adds that it makes sense to stop if you expect to live less than 10 years. The USPSTF says there isn’t enough evidence on the benefits and harms in women aged 75 or older.

What’s the difference between a mammogram and a 3D mammogram?

Both use X-rays to take pictures of your breast. The biggest difference is that a traditional mammogram takes pictures from two angles, while a 3D mammogram uses a machine that takes many images and uses a computer to combine them into a series of thin slices. That gives your doctor more detailed images of your breast tissue. The American Cancer Society recommends both kinds of mammograms but says a 3D mammogram lowers the need for more testing and may be especially useful for people with dense breasts. But insurers don’t always cover it.