Some women have recurring bouts of cystitis, sometimes defined as two proven infections within six months, or three infections in a year.
What is recurrent cystitis?
Cystitis means inflammation of the bladder. It is usually caused by a urine infection. Some women have repeated bouts of cystitis. Doctors define a recurrent infection as either three proven separate infections in a year, or as two in six months. In many cases there is no apparent reason for a woman to get frequent attacks of cystitis.
There are a number of treatment options to consider. This might be treating each episode promptly with a short course of antibiotics, a regular low dose of antibiotics taken long-term, or taking a single dose of antibiotic after having sex (if having sex seems to trigger episodes of cystitis). You can read more about cystitis in the separate leaflet called Cystitis (Urine Infection) in Women.
Why do some women have recurring cystitis?
Your body has defences to prevent germs (bacteria) from causing cystitis. The mucus around your vagina and opening of your urethra is slightly acidic which prevents bacteria from multiplying. Although bacteria may thrive in urine, you empty your bladder regularly which flushes urine out. Also, the cells that line your urethra and bladder have some resistance against bacteria.
In most cases, there is no apparent reason why cystitis returns. There is usually no problem with your bladder or defence (immune) system that can be identified. It is possible there may be a slight alteration in the ability of the body to resist bacteria getting into the bladder and causing infection. A slight variation in the body's defence may tip the balance in favour of bacteria to cause infection. (In a similar way, some people seem more prone to colds, sore throats, etc.)
For some women, one of the following may contribute:
- Bladder or kidney problems may lead to infections being more likely. For example, kidney stones, or conditions that cause urine to pool and not drain properly. Your doctor may arrange some tests if a problem is suspected.
- Having sex increases the chance of cystitis in some women (see below).
- Contraceptive choice: the use of diaphragms and spermicide may make cystitis more likely.
- Hormones: your vagina, bladder and urethra respond to the chemical (hormone) called oestrogen. After the menopause, when the levels of oestrogen in the body reduce, the tissues of these organs become thinner, weaker and dry. These changes can increase the risk of recurrent cystitis. Cystitis is also more common during pregnancy because of changes in the urinary tract.
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What can I do to help prevent cystitis?
Unfortunately there is no evidence that many of the lifestyle changes traditionally advised really help to prevent cystitis. Traditionally, doctors have advised drinking plenty of fluids to 'flush out' the germs (bacteria), and drinking cranberry juice. However, there is no evidence that either of these make any difference. Other changes, such as the way you clean yourself and which underwear you wear, have also not been found to make any difference.
Recently a randomised controlled trial showed that premenopausal women with low daily fluid intake could reduce the numbers of episodes of cystitis by increasing their total fluid intake.
D-mannose is a naturally occurring simple sugar that can be bought in health food shops. Research has shown that taking it daily helps prevent recurrent urine infections. Many guidelines from around the world (including the National Institute for Health and Care Excellence (NICE) now recommend trying this strategy. D-mannose is passed out in your urine and stops bacteria sticking to the wall of your bladder which prevents infection. Most people can take D-mannose without any side-effects but a small number of people (8 out of 100 who had taken it for at least 6 months) may find it gives them diarrhoea.
Researchers are also studying the effects of probiotics (such as lactobacillus) on preventing cystitis. For postmenopausal women who have a less acid environment in the vagina, the idea is that these bacteria would restore the acidity and help prevent infection. But currently there isn't enough evidence to know if they are really useful.
What are the treatment options for recurring cystitis?
Prompt self-treatment of each bout of cystitis
Antibiotic medication is usually needed for the treatment of bouts of recurrent cystitis. If your symptoms are mild then it is usually advisable to wait for the results of your urine test to see which antibiotics you should be treated with. However, if your symptoms are bad or worsening then you should start antibiotics without any delay.
Some women are prescribed a supply of antibiotics to keep on standby. You can then treat a bout of cystitis as soon as symptoms begin without having to wait to see a doctor. A three-day course of antibiotics is the usual treatment for each bout of cystitis. Antibiotics commonly used include trimethoprim and nitrofurantoin.
Ideally, you should do a midstream specimen of urine (MSU) to send to the laboratory before starting to take any antibiotics. You should see a doctor if your symptoms do not go within a few days, or if they worsen.
Antibiotic prevention is another option
This means taking a low dose of an antibiotic regularly. One dose each night will usually reduce the number of bouts of cystitis. A six-month course of antibiotics is usually given.
You may still have bouts of cystitis if you take antibiotics regularly but the episodes should be much less often. If a bout does occur, it is usually caused by a germ (bacterium) which is resistant to the antibiotic you are taking regularly. A urine sample is needed to check on which bacterium is causing any bout of cystitis. You may then need a temporary change to a different antibiotic.
If you have gone through the menopause vaginal oestrogen may be an option
If you have gone through the menopause and had your last natural period (postmenopausal), your hormone levels will have dropped. As explained earlier, this leads to changes in the vagina and the urethra that can increase the chances of getting recurrent cystitis, as well as other problems like dryness and painful sex. You can read more about this in the separate leaflet called Vaginal Dryness (Atrophic Vaginitis).
Vaginal oestrogen has been shown to reduce the number of bouts of cystitis in postmenopausal women who get recurrent cystitis and has a low risk profile compared to antibiotics.
It is usually taken as an estradiol tablet that you insert into your vagina at night twice a week or as a ring that releases estradiol continuously and stays in the vagina for three months at a time. It can help even in postmenopausal women who don't have any of the other vaginal symptoms.
Is recurrent cystitis related to having sex?
Some women find that they are prone to cystitis within a day or so after having sex. This may be partly due to the movements during sex which may push germs (bacteria) up into the bladder.
There may also be slight damage to the urine outlet tube (urethra). This slight damage encourages bacteria to thrive. This is more likely if the vagina is dry during sex. The normal mucus in and around the vagina may also be upset if spermicides or diaphragm contraceptives are used.
The following may reduce the chance of cystitis developing after sex:
- After having sex, go to the toilet to empty your bladder.
- If your vagina is dry, use a lubricating jelly during sex.
- Taking a single dose of antibiotic within two hours after having sex has been proven to reduce the chance of you getting cystitis if you are prone to getting it after sex.
- Do not use spermicides and/or a diaphragm for contraception. See your doctor or practice nurse for advice on other forms of contraception.
Further reading and references
Urinary tract infection (lower) - women; NICE CKS, March 2023 (UK access only)
Kwok M, McGeorge S, Mayer-Coverdale J, et al; Guideline of guidelines: management of recurrent urinary tract infections in women. BJU Int. 2022 Nov130 Suppl 3(Suppl 3):11-22. doi: 10.1111/bju.15756. Epub 2022 May 17.
Rahn DD, Carberry C, Sanses TV, et al; Vaginal estrogen for genitourinary syndrome of menopause: a systematic review. Obstet Gynecol. 2014 Dec124(6):1147-56. doi: 10.1097/AOG.0000000000000526.
De Nunzio C, Bartoletti R, Tubaro A, et al; Role of D-Mannose in the Prevention of Recurrent Uncomplicated Cystitis: State of the Art and Future Perspectives. Antibiotics (Basel). 2021 Apr 110(4):373. doi: 10.3390/antibiotics10040373.
Abdullatif VA, Sur RL, Eshaghian E, et al; Efficacy of Probiotics as Prophylaxis for Urinary Tract Infections in Premenopausal Women: A Systematic Review and Meta-Analysis. Cureus. 2021 Oct 1713(10):e18843. doi: 10.7759/cureus.18843. eCollection 2021 Oct.
Hooton TM, Vecchio M, Iroz A, et al; Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections: A Randomized Clinical Trial. JAMA Intern Med. 2018 Nov 1178(11):1509-1515. doi: 10.1001/jamainternmed.2018.4204.