You are using an older browser version. Please use a supported version for the best MSN experience.

Urine test: why are white blood cells in my urine?

Netdoctor (UK) logo Netdoctor (UK) 12/02/2020 Medically reviewed by Dr Louise Wiseman MBBS, BSc (Hons), DRCOG, MRCGP, words by Annie Hayes
a person holding a toothbrush: White blood cells, also called leukocytes or leucocytes, help protect your body against infections. Constantly made in your bone marrow, they patrol your body and rush to your defence at the first sign of infection. © Peter Dazeley - Getty Images White blood cells, also called leukocytes or leucocytes, help protect your body against infections. Constantly made in your bone marrow, they patrol your body and rush to your defence at the first sign of infection.

There are all sorts of reasons why your doctor might ask you for a urine sample. You might not think it, but your urine says a lot about your general health, so it’s a useful indicator for a whole host of diagnoses.

Should your sample results reveal the presence of white blood cells – otherwise known as your ‘immunity’ cells – you’ll want to pin down the possible causes. Dr Matthew Brown, clinical fellow for Bupa UK, explains what it could mean for your health when white blood cells show up in a urine sample:

What are white blood cells?

White blood cells, also called leukocytes or leucocytes, help protect your body against infections. Constantly made in your bone marrow, they patrol your body and rush to your defence at the first sign of infection.

‘Think of your white blood cells as your immunity cells,’ says Dr Brown. ‘They flow through your blood to fight viruses, bacteria and other sources of infection. White blood cells detect sources of infections and help prevent illness.’

It’s important to note that there usually aren’t any blood cells in urine. When your kidneys filter your blood, removing waste and water to make urine, they don’t allow blood cells to pass through. So what gives?

Why might white blood cells show in urine?

Most causes of white blood cells in your urine are not serious. However, 'it can sometimes mean that you have a medical condition that needs treatment, such as a urine or kidney infection,’ explains Dr Brown.

Why? For similar reasons we see white spots on the throat when we have a sore throat and white heads on our skin when we suffer from infected acne – the white areas are collections of white blood cells, which form pus.

‘It is important to note that white blood cells are not visible in the urine,’ adds Dr Brown. ‘They are usually picked up when a doctor tests a urine sample you have provided. If you notice any visible blood in your urine, it is important that you see your doctor urgently.’

Inflammation is another reason white blood cells may be present in your urine, and this could be caused by kidney stones, immune disorders, allergies or growths anywhere along the genitourinary system.

White blood cells in urine symptoms

What symptoms are associated with white blood cells in urine? This all depends on the health condition causing them to appear. Should a bladder infection be to blame, you may experience pain in your lower tummy, feel tired or unwell, or have a pain when you pass urine, explains Dr Brown.

Kidney stones, another possible cause, can bring about similar symptoms, along with severe back pain, nausea, vomiting or fever. ‘If you’re experiencing any unusual symptoms, it’s best to get them checked out by your GP,’ he adds.

White blood cells in urine tests

What’s the next step? If you do have white blood cells in your urine, your doctor may ask you some questions to find out what has caused it, explains Dr Brown.

If they suspect an infection, they may prescribe you antibiotics and send a sample of urine away for culture and sensitivity to identify any microorganisms.

‘If this happens, it’s crucial you finish the full course of antibiotics, even if you start to feel better,’ Dr Brown says. ‘The doctor may change your antibiotics once they have the results from your urine sample, and if your symptoms have not cleared.’

Should no infection be present, further tests to measure kidney function and to outline the shape of the kidneys using X-rays may be required. Alternatively, your doctor may suggest a cystoscopy, which allows doctors to view the inside of your bladder using a narrow flexible telescope.

‘If the cause isn’t clear, your doctor may request other tests, depending on your age and other symptoms,’ says Dr Brown. ‘It’s important to remember that your doctor should discuss next steps with you. If you do have any questions, it’s best to let your GP know.’

Last updated: 12-02-2020

AdChoices
AdChoices

More from Netdoctor

Netdoctor (UK)
Netdoctor (UK)
image beaconimage beaconimage beacon