Quick answer
A mammogram is the only test recommended to screen women without symptoms for breast cancer: every two years from 40 to 69 under Mexico's official standard (NOM-041-SSA2-2011), and from 40 to 74 under the USPSTF. A breast ultrasound doesn't replace it, but it's the right test if you're under 35 and notice a change, have dense breasts, or need a lump checked. At AVA Médica, our gynecologist performs breast exams and breast ultrasounds by appointment.
Every October brings the same question: “should I get an ultrasound or a mammogram?” The short answer is that they aren't interchangeable. Each test sees different things, and which one you need depends mostly on your age and on whether you've noticed a change in your breasts. Here's what the official guidelines say, in plain language.
What does each test show?
A mammogram is an X-ray of the breasts using a low dose of radiation. Its big advantage is that it detects microcalcifications: tiny specks that can be the earliest sign of a problem, years before a lump can be felt. That's why it's the only test the guidelines recommend for checking women who have no symptoms at all.
A breast ultrasound uses sound waves, not radiation. It's very good at telling whether a lump is a cyst (a small fluid-filled sac that's almost always benign) or something solid, and it works better than a mammogram in dense breasts, which are common in younger women. What it doesn't see well are microcalcifications, so it can't replace a mammogram.
Which one is right for your age
This is what Mexico's NOM-041-SSA2-2011 recommends for women without special risk factors. Your doctor may adjust it based on your history:
| Age | What's recommended | Where ultrasound fits |
|---|---|---|
| 20 to 24 | Breast self-exam, ideally every month | Only if you notice a change |
| 25 to 39 | Self-exam plus a clinical breast exam once a year | First-choice test for symptoms before 35, or for dense breasts |
| 40 to 69 | Mammogram every two years and an annual clinical exam | Add-on when the mammogram shows dense tissue or a lump that needs a closer look |
| 70 and older | Mammogram as directed by your doctor or for follow-up | As your doctor recommends |
One important detail: Mexico's standard doesn't recommend screening mammograms before 40. It isn't forbidden; it's that breast tissue tends to be denser at that age, and ultrasound gives more information when something needs checking.
When ultrasound is the better choice
The standard lists the cases where a breast ultrasound is indicated. The most common are:
- You're under 35 and notice a lump, localized pain, or another change.
- You have dense breasts (your mammogram report or your doctor will tell you).
- A lump needs to be classified as a cyst or a solid nodule.
- You're pregnant and have a breast symptom: ultrasound uses no radiation.
- You have breast implants.
- There's inflammation or infection in the breast, for example while breastfeeding.
And the other way around: the standard is clear that ultrasound shouldn't be used on its own as a screening test for women without symptoms. If you're 40 or older, your routine check is still the mammogram.
Signs you shouldn't wait for your annual check
The standard itself says it: not every lump is cancer, and breast cancer can be treated successfully when it's found early. Even so, any of these changes deserves a prompt visit, whatever your age:
- A new lump or thickening in the breast or armpit.
- A change in the shape or size of a breast.
- Dimpled or puckered skin, or skin that looks like an orange peel.
- A nipple that turns inward, or nipple discharge, especially if it's bloody.
- Redness or warmth in the breast that doesn't go away.
Getting checked matters: according to preliminary INEGI data, breast cancer was the leading cause of cancer death in Mexico in 2024. What makes the difference is finding it early, and that depends on not putting off the visit.
If you live in Texas
The U.S. recommendation is very similar: in 2024 the U.S. Preventive Services Task Force updated its guideline so women get a mammogram every two years from 40 to 74. Many patients from Eagle Pass and Del Rio cross for their exam because here they can explain everything to a gynecologist in Spanish. With the Medical Lane at International Bridge #1, the trip back to the U.S. drops to about 15 to 20 minutes.
Breast exams at AVA Médica
At AVA Médica, our gynecologist performs clinical breast exams and breast ultrasounds, in one place and in Spanish. Unlike general visits, gynecology is by appointment: send us a WhatsApp message and we'll tell you which days are open and whether you need any preparation. If your age calls for a mammogram, we'll guide you on the next step during your visit.
This information is general and does not replace a medical consultation. Always consult your doctor for a personalized diagnosis and treatment.