What is a urine infection and what causes it?
Most urine infections are caused by bacteria (germs) that come from your own bowel. They cause no harm in your bowel, but can cause infection if they get into other parts of your body. Some bacteria lie around your anus (back passage) after you pass a stool (faeces). These bacteria sometimes travel to your urethra and into your bladder. Some bacteria thrive in urine and multiply quickly to cause infection.
The infection is often just in the bladder ('cystitis'). Sometimes it travels up to also affect one or both kidneys. A urine infection is often called a 'urinary tract infection' (UTI) by doctors.
How common are urine infections?
Urine infections are rare in men aged under 50. They become more common in older men. About 3 in 100 men in their 60's, and about 1 in 10 men in their 80's, will have a urine infection. (Urine infection is much more common in women. This is because, compared to men, their urethra is shorter and opens nearer the anus.)
Why do some men get urine infections?
In many cases the infection occurs for no apparent reason. There is no problem with the bladder, kidney, prostate, or defence (immune) system that can be identified. It is just 'one of those things'. In some cases, an underlying problem can increase the risk of developing a urine infection. These include the following.
- An enlarged prostate may stop the bladder from emptying properly. Some urine may then pool in the bladder. Bacteria are more likely to multiply and cause infection in a stagnant pool of urine. An enlarged prostate is a common problem in the over 50's. (Another page discusses prostate enlargement in more detail.)
- 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.
- Having unprotected anal sex increases the risk of infection.
- A poor immune system increases the risk of having any infection, including urine infections. For example, if you have AIDS, or are taking chemotherapy.
What are the symptoms of a urine infection?
- Infection in the bladder (cystitis) usually causes pain when you pass urine, and you pass urine frequently. You may also have pain in your lower abdomen, blood in your urine, and a fever (high temperature).
- Infection in the kidneys may cause pain in a loin (side of the abdomen over your kidney), feeling sick, vomiting, diarrhoea, and feeling generally unwell.
Are any tests needed?
A urine sample can confirm the diagnosis and identify the bacterium causing the infection. Further tests are not usually necessary if you are otherwise well and have a 'one-off' infection. However, your doctor may advise tests of your kidney, prostate, or bladder if an underlying problem is suspected (such as an enlarged prostate or a kidney problem). An underlying problem is more likely if the infection does not clear with antibiotics, or if you have:
- Symptoms that suggest a kidney is infected (and not just the bladder).
- Recurring urine infections. (For example, two or more episodes in a three month period.)
- Had problems with your kidney in the past such as kidney stones or a damaged kidney.
- Symptoms that suggest an obstruction to the flow of urine.
Tests may include a scan of your kidneys or bladder, and/or a look inside your bladder with a special telescope (cystoscopy).
What is the treatment for a urine infections in men?
- A course of antibiotics will usually clear the infection quickly. See a doctor if symptoms are not gone, or nearly gone, after a few days. (Some bacteria are resistant to some antibiotics. This will be identified from the urine sample. A change of antibiotic is needed in some cases if the bacterium is found to be resistant to the first one.)
- Paracetamol or ibuprofen will usually ease any pain, discomfort, or fever.
- Have lots to drink is traditional advice if you have cystitis to 'flush out the bladder'. However, there is no proof that this is helpful. Some doctors feel that it does not help and drinking lots may just cause more (painful) toilet trips. Therefore, it is difficult to give confident advice on whether to drink lots or just to drink normally when you have cystitis.
- An underlying cause such as an enlarged prostate may be found and need treatment.
©EMIS and PIP 2006
