Synonyms
Haematuria, erythruria, erythrocyturia English: hematuria
Introduction
Blood in the urine, also known as haematuria, is a relatively common symptom that can stand for a variety of diseases. In most cases, these diseases mainly affect the kidneys, the urinary tract or the prostate in men. Common and harmless causes are, for example, menstrual blood in women, the consumption of beetroot, which can also stain the urine red, or slight bleeding after an operation on the pelvic floor or the urinary tract.
However, blood in the urine can also indicate serious diseases and must therefore be clarified. If it is accompanied by colicky pain and fever, kidney stones or an inflammation of the prostate are likely. Painless blood in the urine can indicate a malignant disease such as a tumour of the urinary tract (urothelial carcinoma) and must be examined by a doctor.
A basic distinction is made between micro-haematuria, i.e. tiny amounts of red blood cells in the urine that can only be seen under a microscope, and macro-haematuria, where the urine is visibly discoloured with blood. The symptom blood in the urine is divided into two forms with regard to the amount of blood: Micro-haematuria is the occurrence of blood in the urine which is not visible to the human eye, i.e. the urine does not show any red colouring and the blood can only be detected microscopically. In microscopic examination, the visible area is divided into so-called visual fields; up to four red blood cells per visual field are normal.
In contrast, in macrohaematuria, the urine can be seen with the naked eye (macroscopically) has a reddish or brownish colour due to the blood admixture. A visible coloration develops from a quantity of about 1ml of blood per liter of urine. There are numerous causes for the appearance of blood in urine. Possible sources of bleeding can be:
- Microhaematuria
- Macrohaematuria
- Diseases of the kidneys:
- Diseases of the bladder, ureter and urethra:
- Diseases of the prostate: inflammation, tumour
- Physical exertion: Marching hematuria
- Blood coagulation disorders
- Menstruation
Classification by gender
The most common causes of blood in urine in men are kidney disease, as well as diseases of the urinary tract and prostate. A very common disease, which can be accompanied by blood in the urine and severe, colicky pain, is kidney stones or ureteral stones. Kidney stones occur mainly in men between the ages of 30 and 60.
Risk factors include obesity, gout, and a diet rich in protein. Therapeutically, ureteral stones smaller than 5 millimetres can be treated by waiting for a spontaneous loss, while administering painkillers and spasmolytics (e.g. Buscopan®). Larger stones, over 5 millimeters, can be removed by shock wave lithotripsy (ESWL) or under ureteral mirroring.
As a preventive measure, sufficient exercise, plenty of drinking (up to 2.5 l per day) and a reduced consumption of animal fats are recommended. Prostate inflammation can also be accompanied by severe pain when urinating, fever, and blood in the urine. Risk factors for prostate inflammation are bladder voiding disorders and manipulation of the urogenital tract (such as inserting a bladder catheter).
Therapeutically, antibiotics are prescribed for four weeks. Rather rare in men, but possible, especially in older men in need of care with bladder catheters, are urinary tract infections or cystitis, which can also be accompanied by pain when urinating, frequent urination and occasionally blood in the urine. Risk factors are lying bladder catheters and diabetes mellitus.
Antibiotics are administered therapeutically. If the bladder catheter is the source of infection, it should be removed immediately. Another possible cause of blood in the urine is tumours.
The most common tumour in men, which can also be accompanied by blood in the urine, is prostate cancer. Risk factors are mainly age and family predisposition. Prostate cancer can manifest itself through blood in the urine, urinary retention, incontinence, impotence, as well as pain in the bones.
However, since these symptoms appear very late, it is important that men from the age of 45 onwards go for regular check-ups, where prostate cancer can be detected early. The gold standard in the treatment of prostate cancer is the radical removal of the tumour. However, for slow-growing tumours, or older patients, a conservative approach under anti-hormonal therapy may be considered.
Another tumor that is associated with blood in the urine is urothelial carcinoma, a malignant disease that originates in the urinary tract and affects mainly men over the age of 65. It can remain asymptomatic for a long time, and only falls through a painless macrohaematuria (visible blood in the urine). The main risk factor for the development of urothelial carcinoma is smoking.
Therapeutically, if the cancer is detected early, a minimally invasive surgery can be performed. If the tumour is discovered at a late stage or has already grown into the surrounding tissue, a radical operation with removal of the bladder and artificial urinary diversion must be performed. Prognostically, many patients develop recurrences.
Another malignant tumour that is associated with blood in the urine is renal cell carcinoma, the most common kidney tumour, which occurs mainly in men. Risk factors are again smoking, obesity, high blood pressure and chronic kidney failure. Renal cell carcinoma is usually asymptomatic, but can be accompanied by flank pain and macrohaematuria.
Therapeutically, the tumour must always be surgically removed, either as partial kidney resection or as radical kidney removal, depending on the findings. Overall, renal cell carcinoma has a very good prognosis, as it can nowadays be detected early. Other causes of blood in the urine of men can be secondary bleeding during operations or interventions in the urogenital tract or accidents with injuries to the urogenital tract.
Chronic kidney damage, for example from poorly controlled diabetes mellitus or poorly controlled blood pressure, can also lead to microhaematuria (only microscopically visible blood in the urine). If micro-haematuria is present, it is essential to adjust blood sugar or blood pressure to a more optimal level in order to prevent further kidney damage. Finally, blood coagulation disorders or the intake of certain medications can also lead to blood in the urine or to a red coloration of the urine.
The most common and harmless cause of blood in a woman’s urine is menstrual blood. If bleeding occurs outside the regular period, a gynaecological examination should be carried out to rule out pathological processes such as cysts, polyps (benign growths of the uterine lining) or tumours. Another very common cause of blood in the urine of women is cystitis.
Cystitis and urinary tract infections are very common in women, because due to the anatomically very short urethra bacteria can rise much faster and can lead to inflammation. The main signs of a bladder infection are frequent and painful urination, blood in the urine and abdominal pain. If flank pain, fatigue and fever are added, this can indicate an inflammation of the renal pelvis.
A cystitis and a renal pelvic inflammation should be clarified by a doctor and treated with antibiotics. Other causes of blood in the urine of women can be kidney stones and ureteral stones. The main risk factors for this are obesity, gout, a low intake of liquids and a diet rich in protein.
However, rheumatic diseases, such as systemic lupus erythematosus (SLE), can also lead to bloody urine if the kidneys are involved. Rarely, and more common in men, kidney tumours or tumours of the urinary tract can also be the cause of blood in the urine. The most common risk factor for the development of these tumours is smoking and advanced age.
However, injuries, operations or manipulation of the urogenital tract (for example, placing a bladder catheter), blood clotting disorders or the use of certain drugs can also lead to blood in the urine. Blood in the urine of children should always be clarified by a doctor. Triggers can be inflammation of the kidneys and the urinary tract, but also cystic kidneys.
Cystic kidneys are usually congenital diseases that are genetically inherited. Some forms become symptomatic already after birth, others only in childhood or young adulthood. Common to all forms, however, is cyst formation (formation of fluid-filled cavities) which, if left untreated, leads to kidney failure.
Symptoms are blood in the urine, flank pain and proteinuria (excretion of proteins with the urine). Therapeutically, the focus is on early detection of the disease and prevention of renal failure. To this end, substances that damage the kidneys (for example painkillers such as aspirin, ibuprofen or diclofenac) should be avoided at all costs and blood pressure should be optimally adjusted.
However, blood in the urine of small children can also indicate a Wilms tumour. This is the most common malignant kidney tumour in children and occurs mainly between the ages of 2-4 years. The causes are still largely unexplained, but a genetic predisposition is suspected.
Wilms’ tumours are often asymptomatic at first, or are accompanied by fatigue, loss of appetite and a bulging, “thick” abdomen. Rarely are blood in the urine and pain. Since Wilms’ tumours often form metastases at an early stage, the therapy of choice is a radical surgical removal of the kidney with subsequent chemotherapy, possibly with additional radiation.
Overall, however, Wilms’ tumor has a very good prognosis, with about 85% of patients being cured. Another cause of painless macrohaematuria (visible blood in urine) is IgA nephropathy. It occurs mainly in children and young adults, and leads to inflammation of the renal corpuscles (glomeruli).
The cause is still largely unknown, but it is assumed that after slight respiratory tract infections, a faulty antigen-antibody complex is formed, which is deposited in the kidneys and damages them. IgA nephropathy is manifested by frequently recurring, painless blood in the urine. The disease is self-limiting and usually no treatment is necessary. Nevertheless, a doctor should be consulted for clarification and regular check-ups.