Screening means looking for breast cancer in people who have no symptoms. This page gives a short overview of each test and what it is generally used for, including some that are not screening tests. The main guide covers screening in full.
One caution applies throughout. Screening policy differs between countries and between people, and your own doctor or screening service decides what applies to you. Guidance changes, so dates are given for each source.
The tests at a glance
The National Cancer Institute (NCI) in the United States describes several tests that may be used to screen for breast cancer, with mammography being the standard test for most women.1National Cancer Institute: Screening for Breast Cancer Page dated August 2025; lists mammography, MRI, ultrasound, clinical breast exam and self-exam. The table compares them.
| Method | What it uses | Generally considered for | Main limitation |
|---|---|---|---|
| Mammogram (2D) | Low-dose x-rays of each breast | The standard test, at ages each guideline sets | Can miss cancers and give false alarms |
| 3D mammogram (tomosynthesis) | X-rays assembled into thin slices | Used with or instead of a standard mammogram | Not at every center and often costs more |
| Breast MRI | Magnets and radio waves, with contrast dye | Added to mammograms for people at high risk | More false positives; not advised alone or for average risk |
| Breast ultrasound | Sound waves | Investigating a finding; sometimes dense breasts | Not used routinely for screening |
| Clinical breast exam | A clinician feels the breasts and underarms | May be done in some situations | Not enough on its own |
| Breast self-awareness | Knowing how your breasts normally look and feel | Everyone | Supports, but does not replace, imaging |
Mammography, including 3D
A mammogram is a low-dose x-ray of the breast. For a screening mammogram, pictures of each breast are typically taken from two angles, with the breast pressed between two plates so the tissue spreads out.2American Cancer Society: Mammograms Last revised July 2026; describes screening mammograms and 3D mammography. The US Centers for Disease Control and Prevention says that at this time a mammogram is the best way to find breast cancer for most women of screening age.3Centers for Disease Control and Prevention: Screening for Breast Cancer Reviewed September 2026.
Three-dimensional (3D) mammography, also called digital breast tomosynthesis, takes many images as the machine moves in a small arc around the breast, and a computer assembles them into thin slices. The American Cancer Society says studies suggest it appears to lower the chance of being called back for more tests, and that it appears to find some cancers better. It also notes that 3D often costs more and may not be covered by insurance.2American Cancer Society: Mammograms Last revised July 2026; notes lower callbacks, better detection of some cancers and higher cost. The US Preventive Services Task Force (April 2024) calls both digital mammography and tomosynthesis effective.4US Preventive Services Task Force: Breast Cancer Screening Final recommendation statement of April 30, 2024; calls both effective mammographic screening modalities.
Mammograms are imperfect. The American Cancer Society reports that screening mammograms miss about 1 in 8 breast cancers, and that about 1 in 10 screening mammograms are abnormal, though in about 90% of those cases the finding is not cancer.5American Cancer Society: Limitations of Mammograms Last revised July 2026; gives the missed-cancer and abnormal-result figures. See what age to start for timing.
MRI and ultrasound
Breast MRI (magnetic resonance imaging) uses strong magnets and radio waves rather than radiation, and a contrast dye is injected into a vein. The American Cancer Society says that for certain women at high risk, a screening MRI is recommended along with a yearly mammogram, but that MRI is not recommended alone because it can miss some cancers a mammogram would find. It also finds more things that are not cancer, so it is not recommended for average risk.6American Cancer Society: Breast MRI Last revised July 2026; MRI with mammography for high risk, not alone, not for average risk. Its guideline lists examples of higher risk, such as a lifetime risk of about 20% to 25% or greater or a known BRCA1 or BRCA2 gene change.7American Cancer Society: Breast Cancer Screening Guidelines Last revised July 2026; names the higher-risk groups for MRI. See higher risk: family history, genes and other factors for what raises risk.
Breast ultrasound uses sound waves. The American Cancer Society says it is not used routinely for screening, but is used to look at an abnormal area on a mammogram or investigate a lump. An automated whole-breast form may be done as an added screening exam for people with dense breasts.8American Cancer Society: Breast Ultrasound Last revised August 2026; not routine for screening; may be added for dense breasts. The NCI adds that it is not known whether extra ultrasound or MRI for dense breasts leads to better health outcomes.1National Cancer Institute: Screening for Breast Cancer Page dated August 2025; says it is not known whether supplemental ultrasound or MRI improves outcomes in dense breasts. More detail is on the dense breasts page.
Breast exams and self-awareness
A clinical breast exam is a physical exam by a health care provider, who feels the breasts and underarms for lumps or anything unusual. The NCI states it is not an adequate screening test on its own, and the same is said of breast self-exams.1National Cancer Institute: Screening for Breast Cancer Page dated August 2025; neither exam is adequate alone. The American Cancer Society says people should be familiar with how their breasts normally look and feel and should report changes to a healthcare provider right away.7American Cancer Society: Breast Cancer Screening Guidelines Last revised July 2026; advises familiarity with your breasts and prompt reporting of changes. Cancer Research UK uses the term breast awareness, noting that cancers can develop between screening mammograms.9Cancer Research UK: Breast screening (mammography) Last reviewed May 2026; describes breast awareness and interval cancers. See breast changes to tell a doctor about.
Tests that are not screening tests
Thermography, which records heat patterns with an infrared camera, is not an established screening method. The US Food and Drug Administration states that thermography has not been shown to be effective as a standalone test for breast cancer screening and detecting early-stage breast cancer.10US Food and Drug Administration: Breast Cancer Screening: Thermogram No Substitute for Mammogram Consumer update dated October 2023. Details are on the thermography page.
Blood tests are another case. The American Cancer Society describes blood-based tests as used to diagnose, guide treatment or monitor a cancer, rather than as a way to screen well people.11American Cancer Society: Breast Cancer Gene, Protein, and Blood Tests Describes blood and tissue tests for diagnosis, treatment choice and monitoring. The page on whether there is a better test takes this up.
A new lump, thickening, nipple change or other breast change needs a clinician's attention whenever it appears, including soon after a normal mammogram. Your own doctor or screening service can explain which tests apply to you.
References on this page
- National Cancer Institute: Screening for Breast Cancer Page dated August 2025; lists mammography, MRI, ultrasound, clinical breast exam and self-exam.
- American Cancer Society: Mammograms Last revised July 2026; describes screening mammograms and 3D mammography.
- Centers for Disease Control and Prevention: Screening for Breast Cancer Reviewed September 2026.
- US Preventive Services Task Force: Breast Cancer Screening Final recommendation statement of April 30, 2024; calls both effective mammographic screening modalities.
- American Cancer Society: Limitations of Mammograms Last revised July 2026; gives the missed-cancer and abnormal-result figures.
- American Cancer Society: Breast MRI Last revised July 2026; MRI with mammography for high risk, not alone, not for average risk.
- American Cancer Society: Breast Cancer Screening Guidelines Last revised July 2026; names the higher-risk groups for MRI.
- American Cancer Society: Breast Ultrasound Last revised August 2026; not routine for screening; may be added for dense breasts.
- Cancer Research UK: Breast screening (mammography) Last reviewed May 2026; describes breast awareness and interval cancers.
- US Food and Drug Administration: Breast Cancer Screening: Thermogram No Substitute for Mammogram Consumer update dated October 2023.
- American Cancer Society: Breast Cancer Gene, Protein, and Blood Tests Describes blood and tissue tests for diagnosis, treatment choice and monitoring.