Bladder Infection Causes

Medically reviewed by:

Dr Dan Bunstone - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

Bladder infections can occur for two main reasons.

They usually happen when bacteria from the bowels gets into the urinary tract via the urethra and travel up to the bladder. These bacteria live perfectly harmlessly in your gut, but can cause damage if they’re allowed to spread to other areas of your body.

Bladder infections can also be triggered when the bladder becomes irritated or damaged. Some bladder infection risk factors are gender-specific, while others can affect both women and men.

If you recognise any of these potential causes, make sure you let the doctor know during your online consultation, as this will help them with their diagnosis.

Women are at greater risk of bladder infections than men. This is because the female urethra is much shorter, meaning bacteria does not have to travel as far to reach the bladder. The urinary tract also begins much closer to the anus, where the harmful bacteria normally thrive.

Studies suggest that around four million UK women a year will suffer from a bladder infection. A third of women will get some form of urinary tract infection (UTI) before the age of 24, while they are also common in older women.

Common reasons for bladder infections in women include:

Having sex

The thrusting motion that occurs during sex can push bacteria further into the urinary tract. This means they reach the bladder more quickly. The more sex you have, the more likely this is.

Wiping from back to front

After you have a poo, it’s important to wipe away from the urinary tract. Wiping the other way (from back to front) gives bacteria an opportunity to get into the urethra and head for the bladder.

Inserting a tampon

This can push bacteria further down the urinary tract, or cause irritation to the urethra.

Certain types of contraception

In particular, some women have reported that using a diaphragm has contributed to a higher number of bladder infections.

The menopause

The menopause can change the bacterial balance of the vagina and allow harmful bacteria to thrive in the urinary tract.

Pregnancy

As your baby grows, it can start to press against your bladder. This makes it difficult to fully empty your bladder, meaning harmful bacteria aren’t passed out of your body.

bladder infections are rare in men, particularly below the age of 50, they can happen. Here are some of the reasons why:

Enlarged prostate

An enlarged prostate is more likely to occur in men as they get older. As the prostate is found where the urethra meets the bladder, if it becomes enlarged it can cause a blockage in the urinary tract. This can mean the bladder isn’t fully emptied and harmful bacteria may be left behind.

While an enlarged prostate is usually non-cancerous, it’s very important to see a doctor about it, just to rule out potential prostate cancer.

Anal sex

If you give anal sex without a condom, the harmful bacteria found in the anus can enter the urinary tract and lead to bladder infections. This is one of many reasons it’s important to use a condom.

Being uncircumcised

Some studies suggest that bacteria are more likely to enter the urinary tract if they are allowed to build up under the foreskin.

There are some risk factors that can lead to bladder infections in either gender. They include:

Diabetes

If your urine has a high sugar content, it provides a great environment for bacteria to multiply. A potentially harmless level of bacteria can quickly become a problem for a diabetic person.

Inserting or removing a catheter

This can allow bacteria to enter the urinary tract, or cause irritation that can lead to infection.

Using certain soaps or bubble bath

These products can cause irritation if they get into the urinary tract, particularly if they are fragranced.

A blockage in the urinary tract

A bladder or kidney stone can make it difficult to fully empty your bladder. This can mean that harmful bacteria are not passed out of the body as normal.

Drugs

Studies suggest that taking certain illegal drugs, such as ketamine, could increase your chances of getting a bladder infection.

Bladder Infection Causes

Dr Dan Bunstone - Medical Officer

What can cause a bladder infection?

Bladder infection causes in women

Bladder infection causes in men

Bladder infection causes affecting both women and men