Uterine Lining Overgrowth (Endometrial Hyperplasia): What You Need to Know
A thicker-than-normal uterine lining can be harmless, but sometimes it’s a red flag. Uterine lining overgrowth — often called endometrial hyperplasia — happens when the endometrium becomes too thick, usually from extra estrogen. That can cause unusual bleeding and, in some cases, raise the chance of developing endometrial cancer.
What causes uterine lining overgrowth?
Most cases come down to a hormone mismatch: estrogen without enough progesterone. That can happen if you ovulate irregularly or not at all (common with PCOS), if you’re overweight (fat cells make extra estrogen), or if you take estrogen-only hormone therapy. Certain medicines like tamoxifen can also thicken the lining. Age matters too — perimenopause brings more cycles without ovulation, which raises the risk.
Other risk factors include high blood pressure, diabetes, and a family history of endometrial or colon cancer. Smoking oddly lowers estrogen-related risk but has many other harms, so it’s not a protective strategy.
How it shows up and when to see a doctor
The most common sign is abnormal bleeding. That means heavier periods, periods that last longer, spotting between periods, or any bleeding after menopause. Some people notice pelvic discomfort or a change in their menstrual pattern. If you have any unexpected bleeding, especially after menopause, call your doctor. Don’t wait.
At your visit expect a pelvic exam and probably a transvaginal ultrasound. The ultrasound measures lining thickness; in postmenopausal people, a thin lining usually rules out trouble. If the lining looks thick or if bleeding continues, your doctor may do an endometrial biopsy or hysteroscopy to collect tissue and check for atypical cells.
Tissue results guide treatment. Simple hyperplasia without atypia often responds well to progestin therapy. That can be a daily pill or a levonorgestrel IUD (Mirena), which delivers hormone directly into the uterus and works well for many people who want to keep their fertility.
Complex hyperplasia with atypia has a higher cancer risk. Doctors may recommend a hysterectomy for those done with childbearing. If you want to preserve fertility, higher-dose progestin and close follow-up might be an option, but it needs careful monitoring.
To lower your risk: manage weight, treat insulin resistance or diabetes, discuss birth control choices with your provider, and avoid unopposed estrogen. Keep up with medical follow-up if you have irregular cycles or risk factors.
Questions to ask your doctor: What did my biopsy show? Do I need treatment now? Can I preserve fertility? How often should I repeat testing? Clear answers help you move forward with a plan that fits your life and health goals.
If you have abnormal bleeding, don’t ignore it. Early checks and the right treatment usually work well and can prevent worse problems down the line.
