Uterine fibroids, also known as leiomyomas, are common non-cancerous growths that develop in or on the wall of the uterus. These tumors, made of smooth muscle cells and fibrous connective tissue, vary widely in size and often affect women during their reproductive years and into perimenopause. A hot flash is a sudden, intense sensation of heat that typically spreads across the chest, neck, and face, often accompanied by sweating and flushed skin. This experience is a type of vasomotor symptom. Though fibroids and hot flashes are distinct conditions, they frequently occur together, leading many to question if one directly causes the other. This co-occurrence is not a direct cause-and-effect relationship but rather a shared response to the complex hormonal environment within the body.
The Shared Hormonal Environment Linking Fibroids and Hot Flashes
Fibroids themselves do not produce the physiological trigger for hot flashes; instead, both conditions often arise from the same underlying hormonal shifts that define the transition into menopause, known as perimenopause. Fibroid growth is primarily fueled by estrogen, as these tumors possess a higher concentration of estrogen receptors compared to the surrounding uterine muscle tissue. During perimenopause, the body’s hormone production becomes erratic, with progesterone levels often declining before estrogen levels do.
This specific hormonal pattern creates a state often referred to as “estrogen dominance,” where estrogen is unopposed by sufficient progesterone, encouraging fibroid growth. This period is also marked by dramatic, sharp fluctuations in estrogen, which are the main culprits behind vasomotor symptoms. Hot flashes occur when the brain’s internal thermostat, the hypothalamus, is disrupted by a sudden, often erratic drop in estrogen. The brain mistakenly senses the body is overheating and triggers vasodilation and sweating to cool down. The same hormone that feeds the fibroid’s growth when dominant is also responsible for the hot flash when its levels rapidly decline or fluctuate. Therefore, the co-occurrence of growing fibroids and increasing hot flashes is a sign that a person is navigating the unpredictable hormonal landscape of the menopausal transition.
Common Symptoms of Uterine Fibroids
While the hormonal link is often the cause of their co-occurrence with hot flashes, most people are diagnosed with fibroids due to other, more physical symptoms. The location, size, and number of the growths dictate the specific symptoms experienced, which can range from entirely absent to severely debilitating. One of the most common complaints is heavy menstrual bleeding, medically termed menorrhagia, which can lead to iron-deficiency anemia due to significant blood loss over time.
Larger fibroids can create a “bulk effect” by pressing on adjacent organs within the pelvic cavity. This pressure often manifests as a chronic feeling of pelvic fullness or discomfort. If a fibroid presses against the bladder, it can cause frequent urination or a persistent feeling of needing to urinate, even if the bladder is not full. Pressure exerted on the bowels can also result in constipation or difficulty with bowel movements. Fibroids located in the posterior wall of the uterus may also cause chronic lower back pain, as the growth pushes against nerves and muscles in the pelvic region. These symptoms are purely mechanical, resulting from the physical presence of the tumor mass, and are entirely separate from the hormonal fluctuations that cause hot flashes. Addressing these symptoms is often the primary goal when selecting a treatment path for fibroids.
How Fibroid Treatments Impact Hormonal Symptoms
Treatments for uterine fibroids can significantly alter the body’s hormonal state, which may either alleviate or, in some cases, intentionally induce hot flashes. Hormone-altering medications, such as Gonadotropin-Releasing Hormone (GnRH) agonists, are designed to temporarily shrink fibroids by creating a state of medical menopause. They suppress the production of estrogen and progesterone from the ovaries, effectively starving the fibroids of their fuel.
This sudden and profound drop in estrogen is a guaranteed trigger for severe vasomotor symptoms, including intense hot flashes and night sweats. Because of these side effects and the risk of bone density loss, GnRH agonists are typically used only for a short period, often three to six months, sometimes with “add-back therapy” to mitigate the menopausal symptoms. In contrast, non-hormonal procedures like Uterine Fibroid Embolization (UFE), which blocks the blood supply to the fibroid, or a myomectomy, which surgically removes the fibroid, are less likely to directly cause hot flashes.
Surgical interventions like a hysterectomy only impact hot flashes if the ovaries are also removed in a procedure called an oophorectomy. Removing the ovaries immediately halts the body’s natural estrogen production, inducing an abrupt surgical menopause and initiating severe hot flashes. If the ovaries are preserved during the hysterectomy, the body continues to produce hormones, and the person will enter menopause at a more typical age, without the sudden onset of intense vasomotor symptoms.