Conditions and diseases

Bladder infection

Symptoms and causes

Symptoms and causes

What is it?

Many types of bacteria grow in the intestinal tract, the vagina and on the skin. The bladder and urine, on the other hand, are normally sterile: that is, they are free of any bacteria. When bacteria enter the bladder through the urethra and attach themselves there, a bladder infection occurs. Often the exact reason why the bacteria enter and nest cannot be traced, but the following factors are suspected to play a role:

  • Sexual activity: during sexual intercourse, bacteria can transfer via mechanical movements from the anal or vaginal region to the urethra and then into the bladder.
  • Tampons: bacteria can be introduced along with the tampon.
  • Toilet hygiene: when wiping from back to front after stool movements, bacteria can get into the bladder.
  • Urine retention: bacteria can reproduce in the bladder if urination is postponed for a long time and repeatedly.

Bladder infections or cystitis occur frequently in women. Women are more likely to develop cystitis than men. After all, the female urethra is much shorter than the male urethra, which makes it easier for bacteria to reach the bladder.


The typical feeling associated with a bladder infection is the sudden appearance of a frequent, painful pee with an extreme urge to urinate (during the day and often also at night). Lower back pain or pain in the lower abdomen are also possible. The urine is often cloudy and has a bad odour. These symptoms can be very mild, but also very severe.

With a ‘simple’ bladder infection, there is no fever, pain in the side or vomiting. These symptoms are signs that point in the direction of more severe kidney inflammation. Only rarely does a bladder infection lead to kidney infection or other problems.

Diagnosis and treatment

Diagnosis and treatment

How is the diagnosis determined?

Establishing a bladder infection objectively and with certainty is scientifically less easy than you might think. It is generally accepted that the diagnosis of a bladder infection should be based on:

  • the presence of typical symptoms (above)
  • the presence of bacteria and other signs of infection in the urine
  • the disappearance of symptoms after initiating antibiotic treatment

A first important requirement for the diagnosis of a bladder infection is to obtain a ‘mid-stream’ urine sample: urinate with a well-filled bladder, pass the first portion of urine and only collect the second portion (i.e. the ‘mid-stream’ urine) in the urine container. This urine sample should then be sent to a laboratory for a count of the infection cells (pus) and for a urine culture. The urine analysed must always be fresh. If the bladder infection occurs in the evening or on the weekend, the urine sample should be stored in the refrigerator and sent to the laboratory for analysis at a more appropriate time. Please note: the urine sample collected should never be morning urine.


Normally, this condition is easy to treat with a course of antibiotics. It is at least as important to know how to prevent a bladder infection, as it is to know how to treat it.

Preventive measures

Several factors can play a positive role in the prevention of bladder infections:

  • Drink a lot of water: about 1.5 to 2 litres per day.
  • Pee every three to four hours.
  • Drink one glass of cranberry juice a day or take one tablet of cranberry extract a day. The active ingredient of the cranberry can prevent the adhesion of bacteria to the bladder wall.
  • Eat yoghurt containing active bifidus.
  • Always wipe clean from front to back after peeing.
  • Avoid vaginal flushing in the shower (e.g. as a contraceptive method).
  • Avoid the use of highly perfumed items for personal hygiene.

In spite of all these preventive measures, bladder infections will recur in many women. The frequency of bladder infection relapses is highly variable and difficult to predict. Regular bladder infections usually have nothing to do with lifestyle or personal hygiene.


Some forms of bladder infections can go away spontaneously without medication. Usually, however, a short course of antibiotics will speed up healing and minimise annoying symptoms. A long-term course of antibiotics (more than five days) is not recommended. A long-term course of antibiotics typically results in higher costs, more side effects and the development of resistance. In some specific situations, long-term treatment with low-dose antibiotics may be a good option to prevent overly frequent bladder infections.

Higher fluid intake or cranberry intake may also aid in faster healing.

For post-menopausal women, vaginal oestrogen ointment or taking oestrogen tablets may be considered, as they may reduce the risk of relapse of the bladder infection.

When there is a clear link between sexual activity and the onset of bladder infection, a one-time intake of antibiotics after sexual activity can prevent a bladder infection. This treatment option should be discussed with your urologist.

Treatment centres and specialisations

Treatment centres and specialisations

Latest publication date: 12/12/2023
Supervising author: Dr Ameye Filip