Excessive breast compression during mammography may not improve image quality and can cause unnecessary pain. 

False-positive results have been described as “the most frequent harm” associated with mammogram screening, but it actually may be the pain. “There is a wide variation both in the reported frequency of pain and in degree of pain felt by women. There is no doubt that the majority of women feel some degree of pain during mammography.” Why? Isn’t it just a type of x-ray?

For those unfamiliar, I show some photos simulating a mammogram at 0:32 in my video Do Mammograms Hurt?. The breast is sandwiched between two plates and pancaked down. Typical instructions are “‘slowly apply compression manually until the breast feels taut’ and ‘the force of the compression on the x-ray machine should not exceed…20 kg’”—that’s 44 pounds. That’s about the weight of a cinder block pressing down on the breast. No wonder some women experience pain. 

“Studies that attempt quantitative measurement of how much, if any, pain is felt by women undergoing mammography” are all over the place, with the incidence of pain ranging anywhere from 1 to 93 percent, depending on how pain was defined. The discomfort is enough to keep a proportion of women from going back. And what’s the typical line you hear? “Although the compression can be uncomfortable and even painful for some women, it only lasts for a few seconds and is needed to produce a good picture.” This is a sentiment to which one woman replied, “You tell doctor to come on over here…he’s got stuff that can be mashed too, you know…” 

Mammogram compression can cause bruising and has led to the rupture of breast implants, cysts, and blood vessels. Women with dense breasts are often advised to take painkillers or tranquilizers “to endure the procedure more comfortably.” Yet, pain is there for a reason. It’s trying to warn us about potential tissue damage. And, there’s a theoretical concern that tissue inflammation could wake up dormant tumors. That’s sheer speculation at this point, but we should still try to make mammograms less painful. 

The reason they apply so much pressure is “to reduce breast thickness, and by that decrease the radiation dose and improving image quality.” When it was put to the test and actually measured, though, one study found the radiation dose increased at higher compression forces. Another study found that about a quarter of women did not experience a difference in the thickness of their breasts when compression was eased back a bit, which “implies that more compression was applied than necessary. This is an important point since once minimum thickness is achieved further compression only results in more pain with no benefit to image quality.” 

The bottom line is that “pain in mammography is an issue to be taken seriously…Recognising this in the tone and content of patient information and advising on ways to deal with it would show greater respect for patients than blanket reassurance…” The reason women aren’t more up in arms may be that “the majority of women feel compelled (by fear or duty) to comply,” but that just helps the medical establishment push the pain issue to the margins.

There is so much confusion when it comes to mammograms, combined with the corrupting commercial interests of a billion-dollar industry. As with any important health decision, everyone should be fully informed of the risks and benefits, and make up their own mind about their own bodies. This is the sixth in my 14-part series on mammograms. For the others, see:

Nine out of Ten Women Misinformed About Mammograms
Mammogram Recommendations: Why the Conflicting Guidelines?
Flashback Friday: Should Women Get Mammograms Starting at Age 40?
Do Mammograms Save Lives?
Consequences of False-Positive Mammogram Results
Can Mammogram Radiation Cause Breast Cancer?
Understanding the Mammogram Paradox
Overtreatment of Stage 0 Breast Cancer DCIS
Women Deserve to Know the Truth About Mammograms
Breast Cancer and the Five-Year Survival Rate Myth
Why Mammograms Don’t Appear to Save Lives
Why Patients Aren’t Informed About Mammograms
The Pros and Cons of Mammograms


The most frequent harm associated with mammogram screening has been identified as false-positive results, but it may actually be the pain caused by the procedure itself.
In a mammogram, the breast is compressed between two plates and flattened. The compressive force of the x-ray machine is not to exceed 20 kg, which is 44 pounds, about the weight of a cinder block.
Mammogram compression can cause bruising and rupture of breast implants, cysts, and blood vessels.
So much pressure is purportedly applied to reduce the thickness of the breast and “decrease the radiation dose and improv[e] image quality.” However, researchers found a higher dose of radiation at higher compression forces, as well as no difference in the thickness of women’s breasts when compression was reduced, implying that more compression was applied than needed.
And, excessive breast compression during mammography may not improve image quality at all.

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

2019: Evidence-Based Weight Loss

2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers

2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet

2014: From Table to Able: Combating Disabling Diseases with Food

2013: More Than an Apple a Day

2012: Uprooting the Leading Causes of Death