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What Is the Main Cause of Myoma?

Medically reviewed by Jobelle Ann Dela Cruz Bigalbal, MD · General Practitioner

Written by Lorraine Bunag, R.N. · Updated Jun 09, 2021

What Is the Main Cause of Myoma?

Myoma or uterine fibroids are benign tumors made up of fibrous tissues and smooth muscle cells. Reports say that up to 80% of women will develop myoma in their lifetime, but not everyone will exhibit symptoms. For those who will develop symptoms, they may experience pelvic pain, prolonged or heavy periods, difficulty in urination, as well as problems in getting pregnant. But what is the main cause of myoma?

Uterine Fibroids: What you need to know

What Is the Main Cause of Myoma?

Although myoma is the most common benign tumor in women of reproductive age, its main cause is still a mystery.

However, it’s safe to say that myoma or uterine fibroids are “under hormonal control”. This is because almost all cases show patterns that relate to a woman’s progesterone and estrogen levels.

  • Myoma tends to grow rapidly when a woman is pregnant. Experts say it’s likely because the levels of the progesterone and estrogen hormones are high during pregnancy.
  • Interestingly, the fibroids shrink when a patient uses anti-hormone medications.
  • Finally, researchers have determined that the fibroids stop growing or shrink considerably when a woman reaches menopause. As we know, once a woman is in menopause, the levels of estrogen and progesterone drop significantly.

For many doctors, it’s not surprising that hormones contribute the most to myoma development. After all, progesterone and estrogen are the hormones responsible for the proliferation of the uterine lining during each menstrual cycle to prepare for pregnancy.

Scientists also explain that uterine fibroids have more estrogen and progesterone receptors than normal uterine muscles.

But aside from hormones, other factors also increase a woman’s risk of developing uterine fibroids or myoma.

what is the main cause of myoma

What Causes Myoma to Grow: Other Risk Factors

What causes myoma to grow other than the shift in the levels of estrogen and progesterone? According to research, the following factors may come into play:


The relationship between a woman’s age and the development of myoma is a little tricky, but according to studies:

  • Myoma does not occur before puberty; fibroids only grow when the woman reaches childbearing age.
  • Once in their reproductive years, the risk of developing myoma increases with age.
  • For instance, one paper determined that 20-25% of women in their reproductive years had myoma. The prevalence rate then increased to 30-40% for women over the age of 40.
  • The frequency, however, decreases with menopause.

Because of these findings with regards to myoma and age, experts explain that the risk increases with early-onset menarche (first menstrual period) and late-onset menopause.


Aside from the hormones which could be the main cause of myoma, genetics also seem to play a significant role. This means that some women are more predisposed to have uterine fibroid growths than others.

Various studies determined that:

  • Uterine fibroids appear to be hereditary. If you have relatives with myoma, you are at a higher risk of developing it, too. In fact, a woman whose mother had uterine fibroids is 3 times more likely to have benign growths as well.
  • Myoma is also associated with mutations or changes in the following genes: MED12, HMGA, FH, and COL4A5/COL4A6.
  • These genes perform various functions such as protein synthesis, gene expression tuning, enzyme-making, and collagen formation.
  • Ethnicity

    Aside from genes, it seems like ethnicity or race may also cause myoma to grow. According to reports, uterine fibroids are most common among women of the black race. On the other hand, the occurrences seem to be rarest among women in the Asian race.

    Reproductive Factors

    Certain reproductive factors may also determine if a woman will develop uterine fibroids. Consider the following findings:

    • There is an inverse relationship between parity and myoma risk. What it means is that a woman who has given birth at least once is less likely to have uterine fibroids.
    • The risk further decreases the more number of children a woman has.
    • Researchers also noted that an increasing number of term pregnancies decreases the risk of uterine fibroid development.
    • Due to this, experts explain that myoma is most common among “nulliparous” women or those who haven’t had a child yet.

    Diet and Lifestyle

    If hormones are considered the main cause of myoma, several aspects of a person’s diet and lifestyle could be contributing factors.

    • Excess Weight and Obesity. Some studies reveal that obesity could increase the risk of developing uterine fibroids. It’s even possible that obesity could “lessen” the inverse relationship between parity and myoma risk.
    • Diet. Certain factors in a woman’s diet could also cause myoma to grow. For instance, eating too much meat could heighten uterine fibroid growth. On the other hand, a diet rich in fruits and vegetables seems to reduce the risk.
    • Alcohol Consumption. A Japanese study found a strong correlation between alcohol consumption and fibroid risk. In another study, the investigators revealed that the association is “stronger” with beer consumption than wine intake.
    • Micronutrient deficiency. Some micronutrients may also affect the development of myoma. For instance, one study found out that Vitamin D deficiency is associated with uterine fibroid growths.
    • Stress. While there are very few studies about stress and fibroid risk, some researchers believe that it could also be a potential risk factor.

    Menstrual Cycle Explained: Everything You’ve Ever Wanted to Know

    Key Takeaways

    What is the main cause of myoma? For many experts, it could be the hormones estrogen and progesterone. Not only are they responsible for the growth of uterine lining during the normal menstrual cycle, but they are also highly connected to some of the other risk factors (e.g. parity, obesity).

    To reduce your risk, it’s best to eliminate some of the modifiable factors, like stress, micronutrient deficiency, and alcohol consumption. Also, don’t forget to consume a healthy diet and regular exercise to maintain a healthy weight.

    Learn more about Uterine Fibroid here. 


    Hello Health Group does not provide medical advice, diagnosis or treatment.

    Medically reviewed by

    Jobelle Ann Dela Cruz Bigalbal, MD

    General Practitioner

    Written by Lorraine Bunag, R.N. · Updated Jun 09, 2021

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