As fibroids grow, their effect on the body grows as well. Larger fibroids tend to cause a larger, more bothersome variety of symptoms, some with dangerous consequences. For a small percentage of women, growing fibroids can even threaten the health of their kidneys.
What’s the connection between uterine fibroids and kidneys?
It’s incredible how many essential organs are crammed into that not-so-large space within our lower torso. The kidneys, our body’s amazing filtration system, are two fist-sized organs that work constantly to remove excess liquid and the toxins that our body generates as a result of breaking down food to make energy. They package the toxins and liquid together to make urine, and send them down a tube called the ureter to the temporary holding tank known as the bladder. When the bladder gets full enough, it creates the feeling that every human knows well: the urge to urinate.
The uterus is located right above the bladder. When the uterus expands – due to pregnancy, for instance, or due to uterine fibroids – it often presses on the bladder and compresses the storage space, inducing the need to urinate more frequently.
But an expanding uterus can also press on the ureter – the tube that carries the urine from the kidneys down to the bladder. So can fibroids that are external to the uterus and growing in the direction of the ureter. When the ureter is compressed, urine cannot drain from the kidneys easily or completely.
How can fibroids cause damage to the kidneys?
A compressed ureter and incomplete drainage of urine often causes the ureter to swell abnormally: a condition known as hydroureter. Similarly, the backup of urine in the kidney can cause it to swell abnormally: a condition known as hydronephrosis.
If hydronephrosis is temporary and only affects one kidney – as can happen sometimes in pregnancy – then usually there won’t be any symptoms (because the other kidney will take over) and there won’t be any long-term damage (because kidney function will be entirely or mostly restored when the obstruction is removed).
But if hydronephrosis persists for a long time, the nephrons (kidney cells) can die, and the result can be irreversible kidney damage. Even if the obstruction to the ureter is eventually removed, a kidney that has gotten to this point will not regain function.
When only one kidney is affected, as can happen in the case of uterine fibroids pressing on the ureter leading from one kidney, often there won’t be any physical symptoms, or even biochemical markers of kidney function problems in a urine or blood test. The only way to tell is by checking the system of your kidneys and associated organs (called the renal system) using ultrasound.
What precautions should you take to protect your kidneys from damage?
If you have large uterine fibroids, it’s recommended to periodically have an ultrasound examination of your renal system. Remember: even if your kidney function looks fine from a blood or urine test, it could be that one kidney is having a problem, but your other kidney has already compensated for it enough that it is not detectable. The only way to be certain that both kidneys and your ureter are draining properly is to actually take a look using ultrasound.
It is especially important to check the physical condition of your renal system if you do start to experience any of the symptoms associated with hydronephrosis, which include:
- painful urination
- increased urge to urinate
- pain in your back or flank (the side of the body from the upper abdomen to the back)
It’s not easy dealing with uterine fibroids, and adding the renal system to your list of things to be on top of may seem overwhelming. But you deserve a well-functioning body right into your golden years and beyond. Put in the effort to watch out for your kidneys and make sure fibroids aren’t interfering with their function or causing damage. Your future self will be glad you did.