This mucous membrane thickens in anticipation of a possible pregnancy.
If a fertilized egg is implanted, the lining stays in place.
If not, the endometrium thins and sheds as a menstrual period.
Garry DeLong / Getty Images
This article discusses the endometrium, its purpose, and conditions that can affect this tissue.
It also explains how the endometrium’s size and thickness can affect your fertility and health.
Anatomy of the Endometrium
The endometrium is made up mostly of mucosal tissue.
It has two layers.
This layer is an anchor for the endometrium within the uterus and stays relatively unchanged.
The second layer is dynamic, however.
It changes in response to the monthly flux of hormones that guide the menstrual cycle.
For this reason, it’s called the stratum functionalis, or functional layer.
Structures called uterine glands become longer, and tiny blood vessels proliferatea process called vascularization.
This is your period.
Their endometrial linings will stay relatively thin and stable.
Hormonal birth control methods can have a similar effect.
However, this can be altered by abnormalities of the endometrial lining.
Here are the most common ones people may experience.
Periods may be heavy, and you may feel extra tired, bloated, or nauseous.
Endometriosis can be treated with medication, hormone therapy, or surgery, but may still affect fertility.
Endometrial Hyperplasia
In this condition, the endometrial lining becomes too thick.
This most often happens due to a specific hormonal imbalance.
Endometrial hyperplasiacan occur during perimenopause when ovulation becomes irregular or after menopause when the menstrual cycle stops altogether.
This can lead to an extra buildup of the endometrium and, ultimately, heavier periods.
If you experience any of these symptoms, see your gynecologist.
Endometrial hyperplasia can put you at risk of endometrial cancer, as the excess cells can become abnormal.
The condition is usually treated with progestin.
Endometrial Cancer
Endometrial canceriscausedby the growth of abnormal cells.
About 90% of people who are diagnosed with this condition have abnormal vaginal bleeding.
Pain is often the first symptom of endometriosis.
It is unclear whether or not there is a direct link between endometriosis and weight gain.
Many people with endometriosis experience bloating, which can make clothes feel tighter.
Pain may also discourage exercise, which can contribute.
Many people are still able to conceive naturally even with endometriosis.
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