Blood in urine

There are a number of causes for blood in the urine – some common, some serious, and some not so serious, like eating beetroot, which makes it go a purple colour. Strenuous exercise may also cause it.

Urinary infections coming from the bladder or one of the kidneys is the most common cause by far and there are common bacteria (germs) that usually cause this, often originating from the gut (the anatomy is quite close together in that area). These bacteria then enter the sensitive urinary tract and can travel to the bladder and upwards to a kidney. You might experience other symptoms like pain or burning passing urine, difficulty or urgency when urinating, and going to the toilet more often.

Kidney stones may be large and hard, causing bleeding when passing urine as they block the urinary tubes. These typically cause waves of excruciating pain and may also cause a urine infection. If you manage to pass the stone, there will then be a relief from the pain, but you may still have blood in the urine, as the tube has been traumatised.

An enlarged prostate is a common problem in older men. Its size means it can press on the tubes, causing the flow of urine to be blocked and leading to difficulty urinating and possibly blood in the urine.

Cancer is a worrying cause of blood in the urine, and can indicate a more advanced stage of cancer in the prostate, kidney or bladder. Painless blood in the urine is a strong cause of concern, especially in those over 40, and should prompt you to prioritise seeing your doctor. 1 in 5 adults with visible blood in their urine, and 1 in 12 with non-visible blood are subsequently discovered to have bladder cancer.

Certain drugs can also cause blood in the urine, like blood thinners such as warfarin or aspirin, chemotherapy (anti-cancer) drugs and some antibiotics such as rifampicin and nitrofurantoin.

If one of your two kidneys gets injured, for example from a direct blow or trauma, or from an inflammation process such as glomerulonephritis, this can cause bleeding from high up in the urinary system.

If you have blood in your urine, you should always discuss it with your doctor. It is more concerning when you have blood in your urine and the cause is unknown, or if it occurs without pain. If you have blood in your urine and you are experiencing night sweats, weight loss, a change in appetite or increased fatigue, you must speak to your doctor as soon as possible. 

Your doctor will ask you about your symptoms, any relevant medical conditions and any medications or supplements you take. They will ensure the blood is not coming from the vagina or back passage, which may involve an intimate examination. They will ask for a sample of your urine and have tests they can do there and then in their surgery or office, and tests that the lab can do when it’s sent off to hospital.

They will organise for blood tests such as checking for anaemia and kidney function, and may also request an ultrasound or CT scan of your kidneys, ureters and bladder for a greater detailed investigation.

If you have painless blood in your urine and are aged over 40, and you have no signs of infection, your doctor is likely to refer you urgently to a hospital specialist (a urologist).  

Cases of haematuria caused by a urine infection are treated with antibiotics that are prescribed by your doctor.

Specialist input is needed for most of the other causes of blood in the urine. A urologist - a specialist in the urine and kidney system - will organise further investigations, particularly a cystoscopy, where a tiny camera on a long cable is inserted into your urinary system and which can clearly show what’s happening in your bladder.

A kidney stone can be treated through a number of different methods, from seeing if it resolves naturally to surgical management.

If cancer is found to be the cause this will be managed quickly to treat, prevent further damage and prevent any spread.