Adenomyosis is a condition in which the endometrial tissue that normally lines the inside of the uterus grows into the muscular wall of the uterus itself (the myometrium). As a result, the uterus becomes enlarged and thickened, responding abnormally to the monthly hormonal cycle — causing heavy bleeding, severe cramping, and a swollen, tender uterus around menstruation.
Many women confuse adenomyosis with endometriosis because the symptoms overlap considerably. The key difference is location: endometriosis involves tissue growing outside the uterus, while adenomyosis involves tissue growing within the uterine muscle wall. Some women have both conditions simultaneously.
Common symptoms of adenomyosis include periods that are heavier or longer than normal, severe menstrual cramps (dysmenorrhea), chronic pelvic pain, a bulky or tender uterus, and a sense of heaviness or bloating in the lower abdomen. In some cases it can also affect fertility. Symptoms typically worsen with age and improve after menopause.
Diagnosis of adenomyosis can now be made with high-resolution ultrasound or MRI — no surgery required. At THE FIT CLINIC Bangkok, our urogynecology specialists are experienced in identifying adenomyosis and designing personalised treatment plans that may include hormonal therapies, the Mirena IUS, endometrial ablation, or surgical referral when appropriate.
If you have been living with heavy, painful periods for years and dismissing it as "just how you are," it is worth getting a specialist assessment. Treatable pain is not something you have to accept.
Frequently Asked Questions
How is adenomyosis different from fibroids?
Fibroids are non-cancerous muscular growths that develop in or on the uterine wall, while adenomyosis involves endometrial-type tissue infiltrating the muscle itself. Both can cause heavy or painful periods, but they require different management approaches. An ultrasound by an experienced specialist can usually distinguish between them.
Can adenomyosis cause infertility?
Adenomyosis can affect implantation and pregnancy outcomes in some women, though many with the condition conceive without difficulty. If you are trying to conceive and have symptoms consistent with adenomyosis, a thorough urogynecological evaluation is advisable before proceeding with fertility treatment.
What is the best treatment for adenomyosis without surgery?
The hormonal IUS (such as Mirena) is considered one of the most effective non-surgical options — it delivers progesterone locally, reducing bleeding and pain significantly in most women. Combined hormonal contraceptives and GnRH analogues are also used. At THE FIT CLINIC Bangkok, we will assess your individual situation and recommend the most appropriate plan.