Summary: Chronic pain differs significantly from acute pain. It often outlasts the disease that first set it off. A new study shows that persistent pain, like pelvic or lower back pain, in women with repeat UTIs may come from too many nerve endings growing in the bladder. So many women keep hurting long after the infection is gone.
Urinary tract infections (UTIs) are not rare, especially in women past menopause. They cause about 25% of all infections in women. Here is the worry. Even after the infection is wiped out, many women still have lasting or chronic pain.
In other words, many women still report pelvic pain and discomfort in the urinary tract. They feel it even when the infection is fully gone.
This chronic pelvic and lower back pain can cause women a lot of distress. Yet doctors often cannot explain the cause. After all, antibiotics clear the infection in most women.
A new study suggests this lasting pain may come from nerve overgrowth. Extra nerve growth makes nerve cells more sensitive. The result is often chronic pain that is hard to explain.
To study this hard-to-explain pelvic pain, researchers took bladder biopsies (small tissue samples). The patients had a history of repeat urinary tract infections. They still had pain after the infection was gone. The samples showed that their nerve cells were highly activated.
To confirm what they found, the researchers also ran a study in mice. This showed them what drives the nerve overgrowth.
A UTI does a lot of damage to the epithelial cells. That is the top protective layer of the bladder. It also damages nerve cells in the bladder. Once the infection is treated, the bladder starts to rebuild. That includes regrowing the nerve endings that were destroyed.
But it appears that certain immune responses, a natural process, are to blame. Because of them, cells like mast cells release nerve growth factors in massive amounts. In some women, this drives nerve overgrowth. The nerves become more sensitive, and the risk of lasting pain goes up.
The researchers also looked for a way to stop this. When they treated UTIs in lab mice, they also gave drugs that suppress nerve growth factors. This could help cut the risk of lasting pain in mice by preventing the nerve overgrowth.
So this research helps explain the lasting pain that UTI patients have. It also shows how chronic pain differs from acute pain. What works to prevent and manage acute pain would not work for lasting pain or chronic pain syndromes.
Once nerve overgrowth has happened, it is hard to reverse. So this study also shows why early treatment matters to prevent chronic pain. Too often, that window gets missed. Then many patients live with lasting or chronic pain for the rest of their lives.
Last, this study shows that lasting pain may start in a very different way than acute pain. So we need new ways to prevent chronic pain syndromes. And we need new kinds of drugs for different types of chronic pain.
Frequently asked questions
Is it normal to still feel pain after a UTI is gone?
Yes, and it is common. Many women still have pelvic pain and discomfort in the urinary tract after antibiotics fully clear the infection. A 2024 study in Science Immunology traced that pain to an overgrowth of nerve endings in the bladder. The bacteria are gone. But the nerves the infection left behind are more sensitive than before. So the pain outlasts the disease that started it.
Why does my bladder still hurt after a UTI?
A UTI damages the bladder’s protective lining and the nerve cells under it. Once the infection is treated, repair begins. That includes regrowing the destroyed nerve endings. During that repair, immune cells called mast cells release nerve growth factors in massive amounts. In some women this drives nerve overgrowth. The extra, highly activated nerve endings keep sending pain signals long after the infection is gone.
Can recurrent UTIs cause chronic pelvic or lower back pain?
They can. Researchers took bladder biopsies from women with repeat urinary tract infections. These women still had pain after the infections were cleared. The samples showed highly activated nerve cells. The study links that pain to nerve overgrowth. That gives lasting pelvic or lower back pain a physical cause, even when doctors cannot find an active infection.
Can nerve pain after a UTI be reversed?
Once nerve overgrowth has happened, it is hard to reverse. That is why early treatment matters. In lab mice, researchers treated the UTI and at the same time gave a drug that suppressed nerve growth factors. That prevented the overgrowth and lowered the risk of lasting pain. So far this has been shown only in mice. New drugs aimed at this kind of chronic pain are still needed.
Source:
Hayes, B. W., Choi, H. W., Rathore, A. P. S., Bao, C., Shi, J., Huh, Y., Kim, M. W., Mencarelli, A., Bist, P., Ng, L. G., Shi, C., Nho, J. H., Kim, A., Yoon, H., Lim, D., Hannan, J. L., Purves, J. T., Hughes, F. M., Ji, R.-R., & Abraham, S. N. (2024). Recurrent infections drive persistent bladder dysfunction and pain via sensory nerve sprouting and mast cell activity. Science Immunology, 9(93), eadi5578. https://doi.org/10.1126/sciimmunol.adi5578
Dr. Gurpreet Singh Padda, MD, MBA, MHP
