Summary of Pelvic inflammatory disease
Transcript for Pelvic inflammatory disease
Content Reviewers:Evan Debevec-McKenney
Pelvic inflammatory disease
Pelvic inflammatory disease, or PID, is an infection of the upper female reproductive system, including the uterus, fallopian tubes, and ovaries.
It can cause a number of serious complications, including infertility.
The female reproductive system includes all of internal and external organs that help with reproduction.
The internal sex organs are the ovaries, which are the female gonads, the fallopian tubes, two muscular tubes that connect the ovaries to the uterus, and the uterus, which is the strong muscular sack that a fetus can develop in.
The neck of the uterus is called the cervix, and it protrudes into the vagina.
At the opening of the vagina are the external sex organs, and these are usually just called the genitals and they’re in the vulva region.
They include the labia, the clitoris, and the mons pubis.
The vagina, uterus, and fallopian tubes all have a mucosa, which is a layer of epithelial cells that lines the inside of these organs.
PID usually develops from a bacterial infection in the vagina or cervix which causes inflammation of this mucosal layer.
About 60 percent of the time, this changes the composition of the bacterial flora in the vagina, also called bacterial vaginosis.
Because the reproductive tract is essentially one long tunnel that starts at the ovaries and ends at the external sex organs, the infection can travel up the tract pretty easily.
Some mechanisms can make it even easier! For example, the cervical mucus, which normally acts as a barrier preventing bacteria from entering the uterus, may become less effective.
The mucus can become thinner as a result of normal variations throughout the menstrual cycle, or alternatively, it can become less effective in the context of bacterial vaginosis, which is when the normal balance of the vaginal flora is altered, and anaerobic bacteria proliferate and degrade the cervical mucus.
Other factors contributing to an infection may be retrograde menstruation, which is when menstrual blood flows back through the fallopian tubes and into the pelvic cavity instead of out of the body, and also sexual intercourse.
Now, PID is most problematic when the infection reaches the fallopian tubes, in which case it’s called salpingitis.
If it also affects the ovaries, it’s called salpingo-oophoritis.
The infection triggers a response from the body, which sends in neutrophils, plasma cells, and lymphocytes into the fallopian tubes. That sounds like a good thing, right?
But this actually damages the tubal epithelium and the tubes become filled with pus.
When scar tissue forms to repair the damage, areas with damaged epithelium tend to stick to one another, creating closed-off pockets and little dead-end pouches in the fallopian tubes.
This scarring in the fallopian tubes can lead to a number of complications related to PID.
If pus builds up in the tube and ovary, it can turn into an tubo-ovarian abscess, which can be life-threatening if it ruptures.
If a watery fluid builds up in a pocket created by scar tissue in the tubes, this is called hydrosalpinx and it can cause the affected area to become swollen.