Uterine fibroids cause heavy menstrual bleeding, pelvic pressure, frequent urination, constipation, and pain during periods or sex. But here’s what surprises many people: 70 to 80 percent of women develop fibroids before age 50, and most never know it. Only about 20 to 50 percent of women with fibroids experience symptoms at all. When symptoms do show up, they range from mildly annoying to seriously disruptive, depending on the size, number, and location of the growths.
Heavy or Irregular Bleeding
The most recognizable symptom of fibroids is a change in your period. Bleeding becomes heavier, lasts longer, or both. Some women soak through a pad or tampon every hour during their heaviest days, pass large blood clots, or find that periods stretch well beyond seven days. Bleeding between periods is also common.
This kind of blood loss adds up. Over months or years, chronically heavy periods can lead to iron-deficiency anemia, which brings its own set of problems: fatigue, dizziness, shortness of breath, and pale skin. If your periods have gradually become heavier and you’re constantly exhausted, fibroids are one of the most likely explanations.
Pelvic Pressure and Pain
Fibroids are noncancerous growths in and around the uterus, and as they enlarge, they take up space. That physical bulk creates a sense of pressure or fullness in the lower abdomen. Some women describe it as feeling bloated all the time, while others notice their lower belly looks visibly larger. Pain during periods is common too, often more intense than typical menstrual cramps.
Lower back pain and leg pain can also develop when larger fibroids press against nerves in the pelvis. In rare cases, a fibroid can outgrow its own blood supply, causing sudden, severe pain that may require medical attention.
Bladder and Bowel Problems
Fibroids that grow on the outer surface of the uterus can press directly on nearby organs. When the bladder is compressed, you may feel the need to urinate frequently, have difficulty fully emptying your bladder, or experience incontinence. When fibroids press on the bowel, constipation is the most common result.
In rare cases, fibroids can press on the tubes that carry urine from the kidneys to the bladder. This can interfere with kidney function and typically only happens with very large fibroids.
Pain During Sex
Depending on their position, fibroids can make intercourse uncomfortable or painful. This is especially true for fibroids that sit near the cervix or along the front wall of the uterus, where they’re more likely to be compressed during penetration. The pain tends to be a deep ache rather than surface-level discomfort.
How Location Changes What You Feel
Not all fibroids produce the same symptoms. Three main types are grouped by where they grow, and each tends to cause different problems.
- Submucosal fibroids bulge into the inner cavity of the uterus. These are the type most likely to cause heavy bleeding and fertility problems, even when they’re small.
- Intramural fibroids grow within the muscular wall of the uterus. They’re the most common type and can cause heavy periods, pelvic pressure, and pain as they enlarge.
- Subserosal fibroids form on the outer surface of the uterus. They’re more likely to press on the bladder or bowel, causing urinary frequency or constipation, but they’re less likely to affect your period.
Size matters as much as location. A small intramural fibroid may cause no symptoms at all, while one larger than 6 centimeters can distort the uterine cavity enough to affect both menstrual flow and fertility.
Effects on Fertility and Pregnancy
Most fibroids don’t prevent pregnancy. But certain types can make it harder to conceive. Submucosal fibroids and large intramural fibroids (over 6 centimeters) are the ones most associated with decreased fertility. They can change the shape of the cervix, block the fallopian tubes, reduce blood flow to the uterine lining, or make it harder for an embryo to implant.
During pregnancy, the biggest concern is an increased risk of preterm birth or miscarriage. Fibroids can also shift the baby’s position in the uterus, raising the likelihood of a cesarean delivery. If you’re trying to conceive and know you have fibroids, their size and location will determine whether treatment before pregnancy is recommended.
When Fibroids Cause No Symptoms at All
Many fibroids are discovered by accident, during an ultrasound or pelvic exam performed for an unrelated reason. A doctor may feel an irregular shape to the uterus during a routine exam, prompting imaging. If fibroids aren’t causing symptoms, treatment is generally unnecessary. Most fibroids shrink on their own after menopause as hormone levels drop, so a watch-and-wait approach is standard. There’s no evidence that routine imaging follow-up is needed for fibroids that aren’t causing problems.
How Fibroids Are Found
Ultrasound is the first-line tool for confirming fibroids and measuring their size. If more detail is needed, an MRI can map the exact location and type of each fibroid, which helps guide treatment decisions. For women dealing with heavy bleeding or infertility, specialized imaging that uses saline to expand the uterine cavity can give a clearer picture of fibroids growing inside it. Another imaging approach uses dye to highlight the uterine cavity and fallopian tubes on X-ray, which is useful when blocked tubes are a concern.
About 20 percent of women in their forties are actively dealing with fibroid symptoms. If your periods have become noticeably heavier, you feel persistent pelvic pressure, or you’re experiencing urinary changes that don’t have another explanation, fibroids are worth investigating. A pelvic ultrasound can usually confirm or rule them out in a single visit.