Brief overview
- Causes: Inflammation of bladder or urethra, urinary stones, kidney inflammation, kidney infarction, injury to kidneys, bladder or urinary tract, tumors, prostatitis, benign prostate enlargement, schistosomiasis, urogenital tuberculosis, systemic lupus erythematosus, certain medications, and others.
- When to see a doctor? Always, as there may be serious illnesses behind the symptom.
- Diagnostics: physical examination, blood and urine tests, imaging procedures
- Prevention: drink enough, quit smoking, healthy body weight.
Blood in urine: causes and risk factors
Normally, blood is not found in urine. If there is, it indicates a disease or injury in the genitourinary system. This is the system of urinary and reproductive organs.
However, there are other possible causes of bloody or reddish colored urine.
Causes in the urinary tract
Urinary tract infections: Urinary tract infections such as cystitis and urethritis are common causes of blood in the urine. In addition, sufferers often complain of a burning sensation when urinating. Urinary tract infections are also the most common cause of blood in the urine in children.
Kidney inflammation: The collective term kidney inflammation includes inflammation of the renal corpuscles (glomerulonephritis), interstitial nephritis – in which renal tubules and surrounding tissue are inflamed – and inflammation of the renal pelvis (pyelonephritis). All may cause blood in the urine.
Renal cysts: Cysts are fluid-filled cavities that can form in various organs, including the kidney. If they occur singly, they usually do not cause symptoms.
Renal infarction: A renal infarction occurs when a blood clot blocks a renal artery. Sufferers experience sudden pain in the flank.
If a larger part of the kidney tissue is cut off from the oxygen supply by the vessel blockage, abdominal pain, nausea and vomiting are often added to the symptoms. After a few days, blood appears in the urine as a sign of acute kidney failure.
Bladder bilharzia: The tropical disease bilharzia (schistosomiasis) is caused by an infection with pair flukes. Various species of these parasites exist that can cause schistosomiasis.
Some of them prefer to lay their eggs in the veins of the urinary bladder. Sign of this bladder bilharzia is blood in the urine. As the disease progresses, frequent urination and urinary incontinence often occur.
Tumors: sometimes blood in the urine is due to a malignant tumor in the urinary tract, for example, bladder cancer, urethral cancer, ureteral cancer, or kidney cancer (such as renal cell carcinoma).
Other urinary tract and kidney diseases: Diverticula or polyps of the bladder or urethra can also cause hematuria. Diverticula are wall bulges, polyps usually benign mucosal growths.
Injuries: If, for example, the urinary tract, bladder or kidneys are injured in a traffic accident, stabbing, fall or blow, blood often mixes with the urine. It also happens that blood is added to the urine after operations in this region of the body.
Other causes of blood in the urine
In addition, blood in the urine has other possible causes. These include, for example:
Wegener’s granulomatosis: This disease, also called Wegener’s disease or granulomatosis with polyangiitis, is associated with chronic inflammation of blood vessels. In addition, small skin nodules (granulomas) form in the area of the inflammatory processes. If the renal vessels are affected, this results in visibly bloody urine (macrohematuria).
What causes blood in the urine in men?
If blood is found in a man’s urine, it may indicate a problem with the prostate, such as prostatitis or benign prostatic hyperplasia.
Bleeding varicose veins of the prostate (prostatic varices) and prostate cancer are also frequently indicated by blood in the urine.
What causes blood in the urine in women?
The reason for blood in the urine after menopause (i.e. the last menstrual period) is sometimes that the mucous membrane of the genitals and urinary tract has become drier and more sensitive – and thus more susceptible to injury – as a result of the hormonal change. But there may also be a disease behind it, for example a urinary tract infection.
Regardless of a woman’s age, some blood may appear in the urine after sexual intercourse as a result of minor injuries.
Reddish colored urine: not always hematuria
Supposed blood in the urine sometimes turns out to be something other than an elevated level of red blood cells (erythrocytes):
Hemoglobinuria
It occurs, for example, after blood transfusions or heavy physical exertion (such as a long walk) or as part of a poisoning or allergic reaction.
Other possible causes include certain infections such as malaria and hereditary diseases.
Myoglobinuria
In addition to hemoglobulinuria, reddish-brown discolored urine can also be caused by myoglobinuria.
The body subsequently excretes the myoglobin in the urine – this is then called myoglobinuria.
Food and drugs
A completely harmless and temporary red coloration of the urine is caused, for example, by the consumption of certain foods. These include beet, blueberries and rhubarb.
Blood in urine: description
Doctors speak of blood in the urine, or hematuria, when blood, or more precisely red blood cells (erythrocytes), can be found in the urine. These traces of blood can be visible or invisible and can enter the urine at different points in the urinary tract. This results in other terms that are used to describe blood in urine more precisely:
- Macrohematuria: If there are visible traces of blood, i.e. urine that is reddish in color due to blood, this is macrohematuria.
- glomerular hematuria: Here, the cause of the blood in the urine is located in the area of the renal corpuscles (glomeruli) – as in the case of inflammation of the renal corpuscles (glomerulonephritis). The glomeruli represent the first filtering station in urine production: This is where the primary urine is squeezed out of the blood.
Blood in urine: When to see a doctor?
If you notice blood in your urine, be sure to see your health care provider. No matter whether you have additional symptoms such as pain or not. The cause must be clarified and, if necessary, treated accordingly.
This is especially important if a serious disease such as bladder cancer is responsible for the blood in the urine.
Blood in urine: examinations and diagnosis
To clarify the cause of blood in the urine, a series of examinations is necessary. To begin, your health care provider will talk with you at length to get your medical history (medical history). Possible medical questions include:
- When did you notice the blood in your urine? Have you had it before?
- Do you have any other complaints (pain, fever, frequent urination, etc.)?
- Have you recently been in an accident or otherwise injured (e.g., in a fight)?
- Are you currently taking any medications? If yes, which ones?
- If menopause is a possible cause: When was your last period? Do you also have symptoms such as hot flashes or fatigue?
This information will help the doctor narrow down the possible causes of blood in the urine.
Physical examination
Patting and palpation of the abdomen and flanks are also part of the routine. If you feel pain in the flanks, for example, this may indicate kidney disease.
Blood and urine tests
A rapid urine test can be used to check whether you are actually excreting an increased number of red blood cells in your urine (hematuria).
Imaging procedures
The kidneys, bladder and prostate can be examined well with the aid of ultrasound. Physicians assess the renal pelvis and ureter using X-rays.
Computer tomography (CT) and magnetic resonance imaging (MRI) may be useful to rule out tumors above the bladder. In the case of the bladder and urethra, bladder endoscopy (urethrocystoscopy) is used for this purpose.
Tissue samples
Blood in the urine: treatment
Once the cause of blood in the urine is determined, it is targeted for treatment. Some examples:
- In the case of a bacterial urinary tract infection, doctors prescribe antibiotics. The same is true for renal pelvic inflammation.
- An inflammation of the renal corpuscles is usually treated with drugs that suppress the immune system (immunosuppressants such as glucocorticoids or ciclosporin).
- Urinary stones can sometimes be dissolved with medication. Or they are removed during a procedure (e.g., cystoscopy). Larger stones are often broken up using lasers or shock waves before they are taken out or they pass naturally (with the urine).
- In cases of bladder bilharzia, patients are given a drug to treat the worms that cause it (anthelmintic).
- Diverticula and polyps in the bladder or urethra are surgically removed.
- There are various treatment options for menopausal symptoms, including hormone replacement therapy.
- If certain medications are the trigger for the blood in the urine, they are discontinued if possible and/or replaced by alternatives that are gentler on the kidneys.
Blood in the urine: prevention
It is also recommended to give up nicotine: Among other things, smoking promotes the development of cancer in the urinary tract and weakens the immune system. The latter increases the risk of urinary tract infections.
In general, experts recommend drinking enough: at least 1.5 to 2 liters a day. This helps to keep the kidneys and urinary tract healthy and thus prevent blood in the urine, among other things.
Frequently asked questions about blood in the urine
What does blood in the urine mean?
What does blood in the urine look like?
Larger amounts of blood stain the urine pink, red or brown (macrohematuria). In some cases, however, only traces of blood are present in the urine: They are only detectable under a microscope and do not change the color of the urine (microhematuria).
Where can blood in the urine come from?
What should you do if you have blood in your urine?
If you notice blood in your urine, you should see a doctor. It is important to find out the cause of hematuria quickly and treat it professionally. Do not try to treat the problem yourself – there may be a dangerous condition behind it!
What does the urologist do when there is blood in the urine?
What does blood in the urine without pain mean?
Sometimes a medication is the reason when blood in the urine (hematuria) occurs without pain. But it can also be due to a serious disease such as bladder cancer. Therefore, you should have any hematuria – whether without or with pain – clarified by a doctor.
Is it dangerous to have blood in the urine?
When to see a doctor for blood in the urine?
See a doctor immediately if you notice blood in your urine – even if it occurs only once and/or is not associated with pain. It is important to determine the exact cause quickly in order to initiate the appropriate treatment.
