Breast health in perimenopause

By Shweta Arora, MD, board-certified physician · Medically reviewed by Robin Arora, MD · Updated October 2026

Breasts change in your 40s, and so do the questions: Is this lump normal? Do I need a mammogram every year? Is hormone therapy safe for my breasts? Here’s what current guidelines say.

Why breasts change in your 40s

As hormones swing in perimenopause, many women notice tender, full or lumpy breasts, especially before a period. That’s often normal. A new lump or a change that doesn’t go away after a full cycle still needs an exam.

When to start mammograms, and how often

• The U.S. Preventive Services Task Force (2024) recommends a screening mammogram every two years from age 40 to 74.
• The American Cancer Society says women can choose yearly mammograms at 40 to 44, should have them yearly at 45 to 54, and can switch to every two years at 55 and older.
• The American College of Radiology recommends yearly mammograms from 40, and a breast cancer risk assessment by age 25.

The groups differ on how often, but all agree on starting by 40. Choose a schedule with your clinician based on your risk and preferences.

“Your breast tissue is dense”: what the letter means

Since September 2024, the FDA requires every mammogram report and patient letter to say whether your breasts are dense. According to the National Cancer Institute, nearly half of women 40 and older who get mammograms have dense breasts. It’s common and normal, but dense tissue can hide cancers on a mammogram and slightly raises risk.

If you get a dense-breast letter, ask about your overall risk and whether added imaging, such as ultrasound or MRI, makes sense for you. National guidelines don’t yet agree on extra imaging for everyone with dense breasts.

Your personal risk

Family history on both sides, including ovarian, pancreatic and prostate cancer, can change when and how you screen. See genetic testing for women.

Hormone therapy and breast cancer: the real numbers

The Women’s Health Initiative, the largest trial of hormone therapy, found that results depended on the type of therapy. In long-term follow-up published in 2020:

• Estrogen plus a synthetic progestin (for women with a uterus): about 45 breast cancer diagnoses per 10,000 women per year, compared with 36 on placebo.
• Estrogen alone (for women without a uterus): about 30 per 10,000 women per year, compared with 37 on placebo.

Risk depends on your age, the type and dose of hormones, how long you use them and your personal history. The Menopause Society considers the benefit-risk balance favorable for most healthy women under 60 or within 10 years of menopause who have bothersome symptoms. Keep up your mammograms if you use hormone therapy. No blood, saliva or tear test replaces recommended screening.

Everyday risk reducers

• Limit alcohol.
• Stay active. See strength after 40.
• Look after your metabolic health. See midlife weight & heart health.

Every plan is individualized, and treatment is recommended only when it’s right for you after your consultation.

Related reading: Genetic testing for women: what your DNA can and can’t tell you · Do I need my hormones tested? · On hormone therapy but still not yourself?. Browse the full Women’s Health Library.

See us in person or by video

Visit our physician-led team at our Hudson, Ohio or Barboursville, West Virginia office, or meet Dr. Robin Arora by telehealth from anywhere in Ohio, West Virginia, Kentucky or Florida.

Book a prompt visit for a new lump in the breast or armpit, skin dimpling or an orange-peel texture, a nipple that newly turns inward, bloody or clear discharge from one nipple, or one breast that suddenly becomes red, swollen and warm.

Sources: U.S. Preventive Services Task Force, breast cancer screening (2024); American Cancer Society screening recommendations; American College of Radiology (Monticciolo et al., 2023); U.S. FDA Mammography Quality Standards Act final rule (2023, effective 2024); National Cancer Institute, dense breasts; Chlebowski et al., JAMA 2020 (WHI); The Menopause Society 2022 Hormone Therapy Position Statement. This page is general education, not medical advice.