The uterus is a unique organ closely associated with menstruation and reproduction. Many women have no obvious symptoms in the early stage of uterine fibroids, and the symptoms that do appear are highly related to where the fibroids are located.
The uterus consists of two main parts: the uterine body and the cervix. About 80% to 90% of fibroids develop in the uterine body.
The uterine body has different layers, and fibroid symptoms vary accordingly:
- Submucosal fibroids (growing toward the inner lining): often cause heavy menstrual bleeding.
- Intramural fibroids (within the muscular layer): usually asymptomatic in the early stage.
- Subserosal fibroids (growing outward under the outer layer): also tend to be silent at an early stage.
Many patients are only diagnosed during a routine physical examination, with no noticeable symptoms at all.
Most symptomatic fibroids are located in the uterine body. The most common complaint is **abnormally heavy menstrual flow”. Every woman has her own baseline: if she previously used 5 sanitary pads per day but now needs 10 to 20, her bleeding has clearly increased. Average normal menstrual blood loss is about 70 grams, with large individual variation.
Another typical sign is a palpable abdominal mass. Small fibroids cannot be felt, but large ones can be felt as a firm mass in the lower abdomen. Normally, the uterus measures about 5×4×3 cm and remains within the pelvic cavity below the pubic bone. Once it enlarges to the size of a 12‑week pregnancy, it becomes palpable above the pubis and may cause pressure symptoms such as frequent urination or constipation.
An enlarged uterus must be distinguished from pregnancy. Before ultrasound and urine/blood pregnancy tests were widely used, some patients thought they had fibroids only to be found pregnant, leading to misdiagnosis. With modern diagnostic tools, such errors are now extremely rare.