Breast screening explained: tests, ages, results and what comes next

Breast screening means checking for breast cancer in people who have no signs of it.11Centers for Disease Control and Prevention: Screening for Breast Cancer Page updated September 22, 2026; defines screening as checking for cancer before there are signs or symptoms. This guide walks through the tests that are used, what the major guidelines say about ages and intervals, how results are reported, and where screening stops and a conversation with a doctor starts. It describes what recognized bodies publish. It does not tell you whether to be screened, because your own doctor or screening service has the final word and policy differs between countries and between people.

Guidance changes, so every recommendation below is tied to the date shown on the page we read. This guide was reviewed on 11 October 2026. Technical terms are explained where they first appear, and the sources sit in the margin beside the sentences they support.

1. A screening testUsually a mammogram, sometimes with other imaging.
2. A resultRead by a specialist; you are told what was found.
3. Most often: routineBack to the regular schedule of invitations.
4. Sometimes: recallMore pictures or tests to look more closely.
5. If needed: work-upA biopsy and specialist care. A recall is not a diagnosis.

What screening is, and what it is not

Screening is testing people who feel well, with the aim of finding cancer earlier than it would otherwise show itself. It cannot stop breast cancer from developing, and the NHS adds that it is your choice whether to have it.22NHS: Why breast screening is done Page last reviewed 9 October 2025; says screening is your choice, does not stop you getting breast cancer, and that cancer can develop between mammograms. The same page points out that cancer can develop between mammograms, so noticing changes still matters after a normal result.

Diagnosis is a different job. When a person or a clinician finds a lump, or a screening test shows something unclear, further tests are used to work out what it is. The National Cancer Institute (NCI) notes that a diagnostic mammogram uses the same machines as a screening one but takes images from more angles, so the radiation dose is higher.33National Cancer Institute: Mammograms Explains screening versus diagnostic mammograms and notes the higher dose for diagnostic imaging.

The World Health Organization (WHO) divides early detection into two parts. One is early diagnosis, which means recognizing signs and symptoms and seeking medical advice. The other is screening, which it describes as mammography in an apparently healthy population, usually women aged 50 to 69.44World Health Organization: Breast cancer Fact sheet dated 3 July 2026; describes early diagnosis and screening as the two components of early detection.

Mammography: 2D, 3D and what happens

A mammogram is a low-dose X-ray picture of the breast. During the test the breast is placed between two plates and pressed together, which gives a clearer picture, and several images are taken from different angles.33National Cancer Institute: Mammograms Describes the plates, the compression and the multiple images.

Many people worry most about the squeeze. The NHS says screening is often uncomfortable and sometimes painful for some people, that any discomfort should not last long, and that you can ask to stop at any time. It also says the whole appointment should take no longer than 30 minutes.55NHS: What happens at your breast screening appointment Page last reviewed 9 October 2025; covers discomfort, the right to stop, and the 30 minute appointment.

Digital breast tomosynthesis, usually called 3D mammography, takes multiple pictures of thin slices across the breast and assembles them by computer. The NCI says it is better at finding tumors than standard mammography alone, but that it is still unknown whether it does more to reduce deaths from breast cancer.33National Cancer Institute: Mammograms Describes 3D mammography and the open question about deaths, which the TMIST trial is meant to answer.

Radiation is a fair thing to ask about. RadiologyInfo.org, sponsored by radiology societies, says no radiation stays in your body after an X-ray exam, and that some 3D systems give a slightly higher dose than standard mammography while remaining within FDA-approved safe levels.66RadiologyInfo.org: Mammography Last reviewed February 4, 2025; covers radiation and tomosynthesis dose.

Ultrasound, MRI and other tests used in addition

Other imaging tests mostly play a supporting role beside the mammogram. Breast ultrasound uses sound waves and no radiation, and it is mainly used to work out what a lump or a mammogram finding is. It can be offered as extra screening to some people, such as those with dense breasts or those at high risk who cannot have an MRI. The same source says it has a higher false-positive rate than mammography, that early cancers called DCIS often show only as calcifications on a mammogram and are typically not seen on ultrasound, and that it does not replace mammography.77RadiologyInfo.org: Breast Ultrasound Last reviewed June 15, 2026; describes uses, benefits and limitations of breast ultrasound.

Breast MRI, which stands for magnetic resonance imaging, uses magnets and radio waves instead of X-rays. The American Cancer Society (ACS) says people at high risk should typically have a yearly MRI together with a mammogram, and recommends against MRI screening when lifetime risk is under 15 percent.88American Cancer Society: ACS Breast Cancer Screening Guidelines Last revised July 23, 2026; sets out MRI screening considerations and says exams and self-exams are not sufficient for screening.

A clinical breast exam is a physical examination in which a doctor or nurse feels for lumps, and breast self-awareness means knowing how your breasts normally look and feel. Bodies advise differently on these. The ACS does not recommend clinical breast exams for screening average-risk women at any age and says self-exams are not sufficient, yet it still asks everyone to report changes right away. The NHS suggests checking your breasts or chest about once a month so you learn what is normal for you.99NHS: How to check your breasts or chest Page last reviewed 19 July 2024; recommends checking about once a month. Our methods at a glance page lines these up side by side, and is there a better test than a mammogram takes up that question directly.

Thermography and what the FDA says

Thermography produces an infrared image that shows patterns of heat on or near the surface of the body, and it is sometimes put forward as an alternative to a mammogram. The US Food and Drug Administration (FDA) is direct about it: its consumer update says mammography is still the most effective primary screening method for detecting breast cancer in its early, most treatable stages, and that thermography should not be used in place of it. It says it is not aware of any scientific evidence that supports claims that thermography is a proven alternative, and that thermography has not been shown to be effective as a standalone test for screening or for detecting early-stage breast cancer.1010US Food and Drug Administration: Breast Cancer Screening: Thermogram No Substitute for Mammogram Consumer update dated October 2023; says thermography is no substitute for mammography and has not been shown effective as a standalone test.

On its use as a screening tool, the FDA says thermography devices have only been cleared as an adjunctive tool, meaning for use alongside a primary screening test such as mammography, and that people who have thermography alone should not be reassured by the result. It is also not aware of evidence that thermography can find breast cancer years before other methods, or that it improves detection in dense breasts. The update acknowledges why some people look at it, since it is painless and involves no radiation, and advises anyone worried about how a mammogram feels to talk with a health care professional about what to expect.1010US Food and Drug Administration: Breast Cancer Screening: Thermogram No Substitute for Mammogram Consumer update dated October 2023; covers adjunctive clearance, the unproven claims, and the advice to talk with a professional. This site does not endorse thermography or any provider of it. A separate page covers what regulators say about thermography in more detail.

Guidelines by age and risk, in outline

No single guideline applies everywhere, and the major ones disagree about when to start and how often to screen. Each summary below is tied to the date of the page we read, and all of them can change.

The US Preventive Services Task Force (USPSTF), an independent US panel, published its final recommendation on April 30, 2024. It recommends screening mammography every 2 years for women aged 40 to 74 (grade B), and it concludes that the evidence is insufficient to judge the balance of benefits and harms for women 75 or older. It applies to people at average risk, including those with dense breasts or a first-degree relative with breast cancer, but not to people with a BRCA variation, a history of high-dose chest radiation at a young age, or previous breast cancer.1111US Preventive Services Task Force: Breast Cancer Screening Final recommendation statement of April 30, 2024; gives 40 to 74, every 2 years, grade B, an I statement at 75 and over, and who the recommendation does not cover. In England, the NHS Breast Screening Programme automatically invites people registered with a GP as female. As at the NHS page reviewed on 9 October 2025, the first invitation comes between ages 50 and 53, then every 3 years until the 71st birthday, and from 71 you can still be screened every 3 years by contacting your local service.1212NHS: Who breast screening is for Page last reviewed 9 October 2025; gives first invitation between 50 and 53, every 3 years until the 71st birthday.

The Canadian Task Force on Preventive Health Care published draft recommendations on May 30, 2024. Its archived page states that the Task Force ended its mandate on March 31, 2026 and that the content is no longer updated, and the page shows only the draft, with a final guideline promised for a later date. For ages 40 to 49 the draft suggested not screening everyone systematically, but offering mammography every 2 to 3 years to those who want it after learning the benefits and harms. For ages 50 to 74 it suggested screening every 2 to 3 years, and for 75 and over it suggested not screening.1313Canadian Task Force on Preventive Health Care: Breast Cancer (Update), Draft Recommendations (2024) Archived draft; gives 40 to 49 conditional, 50 to 74 every 2 to 3 years, 75 and over not to screen, and finds harms may outweigh benefits at 40 to 49.

The ACS page, last revised July 23, 2026, says people at average risk aged 40 to 44 have the option to start yearly mammograms, those aged 45 to 54 should have a mammogram every year, and those 55 and older can switch to every other year or continue yearly, for as long as they are in good health and expected to live at least 10 more years.88American Cancer Society: ACS Breast Cancer Screening Guidelines Last revised July 23, 2026; gives the average-risk schedule by age. The WHO fact sheet of 3 July 2026 describes screening as mammography usually for women 50 to 69, and says public education on early diagnosis is possible even where mammographic screening is impractical, as it is in many countries at present.44World Health Organization: Breast cancer Fact sheet dated 3 July 2026; gives usual screening age 50 to 69 and notes mammographic screening is impractical in many countries.

1. USPSTF (United States, April 2024)Every 2 years, ages 40 to 74. Evidence for 75 and over judged insufficient.
2. NHS Breast Screening Programme (England)First invitation between 50 and 53, then every 3 years until the 71st birthday.
3. Canadian Task Force (2024 draft, informed choice)Every 2 to 3 years for ages 40 to 74 by personal choice; the draft suggests screening from 50 and not systematically at 40 to 49.
4. American Cancer Society (2026 page)Yearly at 45 to 54, then every 2 years or yearly; option to start at 40 to 44; no fixed stop age (continue while in good health).
5. WHO (2014 position paper)Organized programs for ages 50 to 69, every 2 years.

• 30
• 40
• 50
• 60
• 70
• 80

The 40s show the disagreement most clearly. The USPSTF recommends screening every 2 years from age 40, while the Canadian draft found that for ages 40 to 49 the harms may outweigh the benefits. The bodies are reading overlapping evidence and weighing it differently, which is why the numbers differ. Where you live, your own history and your preferences all shape which advice applies. Our page on what age to start and stop goes through the same comparison in more depth.

Higher risk: family history, genes and chest radiation

Average-risk schedules do not fit everyone, and higher risk usually means different tests, often at a younger age. The ACS defines average risk as having no personal history of breast cancer, no strong family history, no known gene change such as in a BRCA gene, and no chest radiation therapy before age 30. For people at high risk, it advises a yearly breast MRI plus a mammogram, typically starting at age 30. That group includes people with a lifetime risk of about 20 to 25 percent or more by family-history tools, a known BRCA1 or BRCA2 gene change, a first-degree relative with such a change and no testing of their own, chest radiation before age 30, or certain rare syndromes.88American Cancer Society: ACS Breast Cancer Screening Guidelines Last revised July 23, 2026; defines average and high risk.

In England, the NHS says several close relatives with breast or ovarian cancer, a change in BRCA1, BRCA2 or TP53, or dense breast tissue can mean a higher chance of breast cancer. A GP may refer such a person to a genetic specialist, and the person may be invited before 50, more often than every 3 years, or have MRI as well as mammograms.22NHS: Why breast screening is done Page last reviewed 9 October 2025; describes moderate and high risk and how screening may change.

Risk factors are common, and few are decisive on their own. The CDC lists age, certain gene changes, reproductive history, dense breasts, a personal or family history, and chest radiation before age 30, among others, and notes that having a risk factor does not mean you will get the disease.1414Centers for Disease Control and Prevention: Breast Cancer Risk Factors Page updated September 22, 2026; lists risk factors you can and cannot change and says most women with risk factors do not get breast cancer. Most women have some risk factors, the CDC says, and most do not get breast cancer. If you are unsure where you sit, what makes you high risk sets out the factors, and a doctor can place you using your own history.

Understanding your results: normal, recall and BI-RADS

After screening, a letter usually says one of two things: nothing was seen, or more tests are needed. In England the NHS says results usually arrive by letter within 2 weeks, and that if there is no sign of breast cancer you need no further tests and are invited again in 3 years if under 71. Being asked back is called a recall, or a callback. It means more pictures or tests, such as an examination, extra mammograms, an ultrasound, or a biopsy, which is taking a small sample of tissue with a needle. It is frightening to read, and the NHS says most people who need further tests will not be diagnosed with breast cancer.1515NHS: Your breast screening results Page last reviewed 9 October 2025; covers timing, normal results, further tests, and that most people who need further tests are not diagnosed with cancer. RadiologyInfo.org puts a number on it: 5 to 15 percent of screening mammograms need more testing, most of which turns out to be normal.66RadiologyInfo.org: Mammography Last reviewed February 4, 2025; gives the 5 to 15 percent figure for additional testing and advises asking when results will be available.

Radiologists summarize findings with BI-RADS, the Breast Imaging Reporting and Data System, a seven-category scale. In the RadiologyInfo.org description, category 0 means the test is incomplete and more imaging is needed, 1 is negative, and 2 is benign, meaning noncancerous. Category 3 is probably benign, with about a 2 percent chance of cancer and a follow-up scan in six months. Category 4 is suspicious and a biopsy is recommended, split into 4A (2 to 10 percent likelihood of cancer), 4B (10 to 50 percent) and 4C (50 to 95 percent). Category 5 carries a 95 percent chance of cancer, and 6 is reserved for cancer already confirmed by biopsy.1616RadiologyInfo.org: How to Read Your Breast Imaging Report using BI-RADS Last reviewed September 9, 2024; lists the seven categories, the stated likelihoods, and that a BI-RADS score is not a diagnosis.

1. 0Incomplete
2. 1Negative
3. 2Benign
4. 3Probably benign
5. 4Suspicious
6. 5Highly suggestive of malignancy
7. 6Known biopsy-proven malignancy

A BI-RADS number is a way for the radiologist to communicate with your doctor, not a diagnosis, and the biopsy result is what provides one. If you have not heard anything, radiology societies advise asking when results will be available rather than assuming they are normal. The page BI-RADS categories explained goes through each category in turn.

Dense breasts and screening

Dense breasts are common, are not a disease, and can make a mammogram harder to read. Breast density describes the relative amounts of glandular and fibrous tissue compared with fat as seen on a mammogram, and the NCI says nearly half of women aged 40 and older who get mammograms are found to have dense breast tissue. You cannot feel density yourself, and neither can a doctor during a physical exam. Only a radiologist looking at a mammogram can tell.1717National Cancer Institute: Dense Breasts: Answers to Commonly Asked Questions Defines density, says nearly half of women 40 and older who get mammograms have dense tissue, and gives the four categories with approximate proportions.

Reports use four categories: almost entirely fatty, scattered fibroglandular tissue, heterogeneously dense and extremely dense. These are found in about 10, 40, 40 and 10 percent of women respectively, and "dense" means either of the last two.

1. AAlmost entirely fatty
2. BScattered areas of fibroglandular density
3. CHeterogeneously dense
4. DExtremely dense

Density matters for two reasons. Dense tissue and many abnormalities both look white on a mammogram, so mammography is less sensitive and more likely to miss cancer, and people with dense breasts may be called back more often. Separately, dense breasts are a risk factor for breast cancer, so people with them have a higher risk than people with fatty breasts.1717National Cancer Institute: Dense Breasts: Answers to Commonly Asked Questions Explains reduced sensitivity, more callbacks and dense breasts as a separate risk factor.

Whether extra imaging helps is unsettled. The USPSTF concludes that the evidence is insufficient to assess the balance of benefits and harms of supplemental ultrasound or MRI for people with dense breasts and an otherwise negative mammogram.1111US Preventive Services Task Force: Breast Cancer Screening Gives an I statement for supplemental screening in dense breasts.

In the United States, since September 10, 2024 mammography facilities have had to tell patients their density category in a plain-language summary, using wording that says dense tissue makes cancer harder to find and raises the risk of developing breast cancer.1818US Food and Drug Administration: Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA) Gives the required dense and not dense notification statements. If you are told you have dense breasts, ask your doctor what it means for you. Our page dense breasts and screening covers the questions to bring.

Benefits and harms: false positives, overdiagnosis and missed cancers

Screening has real benefits and real costs, and the honest picture includes both. On the benefit side, the ACS says people who have regular mammograms are more likely to have cancer found earlier, less likely to need aggressive treatment such as mastectomy and chemotherapy, and more likely to be cured.88American Cancer Society: ACS Breast Cancer Screening Guidelines Last revised July 23, 2026; summarizes benefits and limitations of regular mammograms. The USPSTF concludes with moderate certainty that screening every 2 years from 40 to 74 has a moderate net benefit. Its modeling estimates a median of 8.2 breast cancer deaths averted per 1,000 women screened over a lifetime, across six models.1111US Preventive Services Task Force: Breast Cancer Screening Gives the moderate net benefit conclusion and the modeled 8.2 deaths averted per 1,000.

The harms have names worth learning. A false positive is a result that looks like cancer but is not, and it is the most common harm: the USPSTF models 1,376 false-positive results per 1,000 women screened every 2 years from 40 to 74 over a lifetime, which counts results, so one person can have more than one. Overdiagnosis means finding a cancer that would never have caused symptoms or problems. It cannot be seen in any one person, only estimated across a screened group, with trial-based estimates of roughly 11 to 19 percent of diagnosed cancers and modeling of 14 overdiagnosed cases per 1,000 people screened over a lifetime, in a wide range of 4 to 37 across models.1111US Preventive Services Task Force: Breast Cancer Screening Gives the 1,376 modeled false-positive results per 1,000, trial-based overdiagnosis estimates of 11 to 19 percent, and 14 per 1,000 modeled with a range of 4 to 37. The NHS names treatment of cancers that would not have been life-threatening as the main risk of screening, because doctors cannot always tell which cancers will become dangerous.22NHS: Why breast screening is done Names overdiagnosis as the main risk of breast screening.

Missed cancers are the third harm. A false negative is a mammogram that looks normal when cancer is present, and the USPSTF lists these among the potential harms of screening. A cancer diagnosed between screening rounds is called an interval cancer, and it reflects a mix of cancers missed earlier and cancers that emerged since.1111US Preventive Services Task Force: Breast Cancer Screening Lists false negatives as a potential harm and defines interval cancers as those diagnosed between screening rounds. See benefits and harms of screening for a longer treatment.

Costs, access and preparing for an appointment

What you pay, and how you get an appointment, depends heavily on where you live. In the United States, the NCI says insurance plans governed by the Affordable Care Act must cover screening mammograms every 1 to 2 years for women 40 and over without copayments, coinsurance or deductibles, and that Medicare pays for annual screening mammograms from age 40. It also says you may be able to book directly with a facility without a referral.33National Cancer Institute: Mammograms Covers insurance coverage, Medicare, self-scheduling and where to get a mammogram. For people without adequate insurance, the CDC's national program offers free or low-cost screening to eligible people, including those aged 40 to 64 with income at or below 250 percent of the federal poverty level.1919Centers for Disease Control and Prevention: Find a Screening Program Near You Page updated September 18, 2026; gives the eligibility rules.

In England invitations come automatically, and if you have not been invited by 53 and think you should have been, the NHS says to contact your local screening service.1212NHS: Who breast screening is for Says to contact the local service if not invited by 53. Questions about asking for a test yourself are taken up in can I ask for a mammogram, and costs and access covers the money side more broadly.

Preparing is mostly practical. The NHS suggests a top that is easy to remove, taking off necklaces and nipple piercings, and skipping deodorant, antiperspirant and talcum powder on the day, and it invites you to tell staff if you are nervous or have found screening uncomfortable before.55NHS: What happens at your breast screening appointment Page last reviewed 9 October 2025; lists preparation tips and the right to ask for support. There is more in preparing for a screening appointment.

When it is not screening: breast changes to tell a doctor about

Screening is for people without symptoms, so a new breast change calls for a clinician rather than a wait for the next invitation. The NHS lists a lump or swelling in the breast, chest or armpit, dimpling or redness of the skin, a change in the size or shape of a breast, nipple discharge that may contain blood, a change in the nipple, and sores on the chest.99NHS: How to check your breasts or chest Page last reviewed 19 July 2024; lists symptoms, says they are very common and can have other causes, and when to see a GP.

That reassurance runs in both directions. The WHO says people with an abnormal breast lump should seek medical care even if it does not hurt. Most breast lumps are not cancer, it adds, and cancers found when small are more likely to be treated successfully.44World Health Organization: Breast cancer Fact sheet dated 3 July 2026; says most lumps are not cancer and a lump should be checked even if painless. Even so, a symptom is a reason to be seen, not to wait. More detail is in breast changes to tell a doctor about.

When a result reaches the people around you

A screening result rarely stays with one person. A recall letter can bring worry to a partner, a parent or an adult child as well as to the person who received it. The NHS acknowledges that you may feel anxious about further tests, and says the letter explains how to contact a breast care nurse with questions.1515NHS: Your breast screening results Says you may feel anxious about further tests and can contact a breast care nurse. If a result, or a later diagnosis, is putting strain on a relationship, our page on couples and cancer looks at how counseling can help.