Hematuria is defined as ≥3 red blood cells per high-powered field of view in centrifugally sedimented urine, or more than 1 in non-centrifuged urine or more than 100,000 in 1-hour urine red blood cell count, or more than 500,000 in 12-hour urine sediment count, all indicating an abnormal increase of red blood cells in urine, and is a common urological symptom. The causes are urinary tract inflammation, tuberculosis, stones or tumors, trauma, drugs, etc., which have very different effects on the organism.
In mild cases, only an increase in red blood cells is found microscopically, which is called microscopic hematuria; in severe cases, the appearance is washed water-like or contains blood clots, which is called sarcoid hematuria. Usually when there is 1mL of blood per liter of urine, it is visible to the naked eye and the urine is red or washed with water.
When red urine is found, it is important to first distinguish whether it is true or false hematuria. Some drugs can cause red urine, such as aminopyrine, phenytoin sodium, rifampin, phenol red, etc.; they need to be distinguished from true hematuria. In recent years, there has been an increasing trend of hematuria without obvious accompanying symptoms, mostly glomerular hematuria, which has attracted widespread attention and research.
I. Etiology
1.Kidney and urinary tract diseases
(1) Inflammation Acute and chronic glomerulonephritis, acute and chronic pyelonephritis, acute cystitis, urethritis, urinary tuberculosis, mycobacterial infection of the urinary system, etc.
(2) Stones Stones in the renal pelvis, ureter, bladder, urethra, or any part of the body can easily cause both hematuria and secondary infection when the stones move through the urinary tract epithelium. Large stones can cause urinary tract obstruction and even renal function damage.
(3) Tumors Malignant tumors in any part of the urinary system or malignant tumors in neighboring organs can cause hematuria when they invade the urinary tract.
(4) Trauma is a violent injury to the urinary system.
(5) Congenital malformation Polycystic kidney, congenital ultra-thin glomerular basement membrane, nephritis, nutcracker phenomenon (the disease is caused by congenital malformation of the blood vessels causing compression of the left renal vein that travels between the abdominal aorta and the superior mesenteric artery, resulting in intractable microscopic hematuria. The right renal vein injects directly into the inferior vena cava, while the left renal vein must cross the angle formed by the abdominal aorta and superior mesenteric artery to inject into the inferior vena cava. Normally, this angle is 45°-60°, but if it is congenitally too small or filled with mesenteric fat, enlarged lymph nodes or peritoneum, it can cause nutcracker phenomenon. Diagnosis is mainly based on CT, ultrasound, and renal venography. Treatment must be surgically corrected).
2.Systemic diseases
(1) Bleeding disorders Thrombocytopenic purpura, allergic purpura, hemophilia, leukemia, malignant histiocytosis, aplastic anemia, etc.
(2) Connective tissue diseases systemic lupus erythematosus, dermatomyositis, polyarteritis nodosa, scleroderma, etc.
(3) Infectious diseases Leptospirosis, epidemic hemorrhagic fever, filariasis, infectious bacterial endocarditis, scarlet fever, etc.
(4) Cardiovascular diseases Congestive heart failure, renal embolism, renal vein thrombosis.
(5) Endocrine metabolic diseases gout kidney, diabetic nephropathy, hyperparathyroidism.
(6) Physicochemical factors such as food allergy, radiation exposure, drugs (such as sulfonamide, phenol, mercury, lead, arsenic poisoning, massive infusion of mannitol, glycerol, etc.), toxins, after exercise, etc.
3.Neighboring organ disease
Tumors of uterus, vagina or rectum invade the urinary tract.
II. Clinical manifestations
1.Change of urine color
The main manifestation of hematuria is the change of urine color. In addition to the normal color of microscopic hematuria, naked eye hematuria has different colors according to the amount of bleeding. The urine is light red like washing meat water, which indicates that the amount of blood per liter of urine is more than 1 mL. When the bleeding is serious, the urine can be blood-like. In the case of kidney bleeding, the urine is evenly mixed with blood, and the urine is dark red; in the case of bladder or prostate bleeding, the urine is bright red, and sometimes there are blood clots.
2.Segmental urine abnormalities
The whole urine will be segmented to observe the color, such as urine three cups test, with three clean glasses were left in the beginning section, middle section and final section of urine observation, such as the beginning section of hematuria suggests that the lesion in the urethra; the final section of hematuria suggests that the bleeding site in the bladder neck, the triangle or the prostate and seminal vesicle gland in the posterior urethra; three sections of urine are red that the whole hematuria, suggesting that the hematuria from the kidney or ureter.
3.Nephrogenic or post-nephrogenic hematuria
The color of microscopic hematuria is normal, but microscopic examination can identify hematuria and can determine whether it is renal or postrenal hematuria. Microscopic red blood cells of various sizes and patterns are glomerular hematuria, which is seen in glomerulonephritis.
4.Symptomatic hematuria
Hematuria is accompanied by systemic or local symptoms in patients. And the urinary symptoms are mainly. If accompanied by dull pain or colic in the kidney area suggests that the lesion is in the kidney. Bladder and urethra lesions are often associated with urinary frequency and urgency and difficulty in urination.
5.Asymptomatic hematuria
Some patients with hematuria have neither urinary tract symptoms nor systemic symptoms, which can be seen in the early stage of certain diseases, such as renal tuberculosis, renal cancer or early bladder cancer.
6.Concomitant symptoms
Hematuria with renal colic is a characteristic of kidney or ureteral stone;
②Hematuria with interrupted urine flow is seen in bladder and urethral stones;
③Hematuria with fine urine flow and difficulty in urination is seen in prostatitis and prostate cancer;
④Hematuria with urinary frequency and urgency and pain is seen in cystitis and urethritis, accompanied by lumbago, high fever and chills is usually pyelonephritis;
⑤ Hematuria with edema, hypertension and proteinuria is seen in glomerulonephritis;
(6) Hematuria with renal mass, unilateral can be seen in tumor, hydronephrosis and renal cyst; bilateral enlargement is seen in congenital polycystic kidney, touching mobile kidney is seen in renal prolapse or wandering kidney;
(7) Hematuria with bleeding from skin mucosa and other parts is seen in hematological diseases and certain infectious diseases; (8) Hematuria combined with celiac disease is seen in filariasis and chronic pyelonephritis.
III. Examination
1.Inquiry into medical history
①The color of urine, such as red, should be further understood whether to consume drugs or food that cause red urine, whether it is during women’s menstruation, in order to exclude pseudohematuria;
②In which part of the urinary process does the hematuria appear, whether the whole process is hematuria, and whether there are blood clots;
③Whether it is accompanied by systemic or urinary system symptoms;
④A history of recent trauma to the lower back and abdomen and urinary tract instrumentation;
⑤ Whether there is any history of hypertension and nephritis in the past;
⑥Whether there is any history of deafness and nephritis in the family.
2.Localization analysis for checking hematuria
The following three types of hematuria can be distinguished by the urine three-cup test.
(1) Primary hematuria Hematuria is only seen at the beginning of urination and the lesion is mostly in the urethra.
(2) Terminal hematuria Hematuria occurs at the end of urination and the lesion is usually in the bladder triangle, bladder neck or posterior urethra.
(3) Complete hematuria Hematuria appears during the whole process of urination, and the bleeding site is mostly in the bladder, ureter or kidney.
3.Routine examination methods
(1) Tubular pattern in urine sediment Especially the red cell tubular pattern indicates that the bleeding comes from the renal parenchyma and is mainly seen in glomerulonephritis.
(2) Urine protein measurement Hematuria with more severe proteinuria is almost always a sign of glomerular hematuria.
(3) Urine containing immunoglobulin in a granular tubular form (IGM).
(4) Urine red blood cell morphology Examination of urine sediment with a bitemporal microscope is currently the most common method for identifying glomerular or non-glomerular hematuria. When the urinary red blood cell count >8×106/L, including >30% of anomalous red blood cells (ring-shaped, target-shaped, budding cell-shaped, etc.), it should be regarded as glomerular hematuria. Urinary protein quantification >500 mg/24 hours in urine is often suggestive of glomerular hematuria.
If there is bleeding from the renal pelvis, ureter, bladder or urethra (i.e., non-glomerular hemorrhage), the formation of red blood cells is overwhelmingly normal in size, and only a small percentage are abnormal red blood cells. If the hematuria is caused by glomerular disorders, the vast majority are aberrant red blood cells, accounting for more than 75% of them, and their morphology varies and their size varies significantly.
IV. Diagnosis
The cause of hematuria can be analyzed in terms of whether it is accompanied by other symptoms. Asymptomatic hematuria should be firstly considered the possibility of urinary tract tumor; hematuria with pain, especially with colic should be considered urinary stones; if accompanied by urinary pain and interruption of urine flow, bladder stones should be considered; if accompanied by obvious bladder irritation symptoms, urinary tract infection, urinary tuberculosis and bladder tumor are more common. In addition, the cause of hematuria should be judged comprehensively by combining the patient’s medical history, age, color and degree of hematuria, etc.
V. Differential diagnosis
Red urine is not necessarily hematuria, but needs to be carefully identified. If the urine is dark red or soy sauce-colored, not cloudy and without precipitation, and there are no or only a few red cells on microscopic examination, see hemoglobinuria; brownish red or wine-colored, not cloudy, no red cells on microscopic examination see porphyriuria; taking certain drugs such as rhubarb, rifampin, or eating certain red vegetables can also discharge red urine, but there are no red cells on microscopic examination.
VI. Treatment
Patients with hematuria must rest in bed and minimize strenuous activities. Drink plenty of water to speed up the excretion of drugs and stones. Those with nephritis who have edema should drink less water. Use drugs that cause hematuria with caution, especially in patients with kidney disease. If hematuria is caused by urinary tract infection, oral and injectable antibiotics and urinary tract cleansers may be used. The causes of hematuria are complex and some of them are very serious, so you should go to a specialist hospital as soon as possible to check and confirm the diagnosis and treat it early.
1.Actively treat inflammation of the urinary system, stones and other diseases.
2.In ordinary life, you cannot often make the bladder highly filled. Feel the urge to urinate, that is, to urinate, in order to reduce the retention of urine in the bladder for too long.
3, pay attention to the combination of work and rest, and avoid strenuous exercise.
In conclusion, if hematuria is found, early examination, diagnosis and timely treatment should be carried out; if it is difficult to be diagnosed for a while, regular re-examination is needed.
7.How to determine the source of hematuria?
How to determine the source of hematuria? When finding hematuria, we should first determine whether it is true hematuria, that is, we should exclude pseudo-hematuria and red-colored urine caused by certain reasons, such as menstruation, bleeding hemorrhoids or bleeding from diseases near the urethra mixed into the urine;
In the latter case, hemoglobinuria or myoglobinuria can be caused by exposure to certain pigments or drugs such as rifampin, as well as certain poisons (phenol, carbon monoxide, chloroform, snake venom), drugs (sulfonamide, quinine), crush injuries, burns, malaria, wrong type of blood transfusion, etc., while transient hematuria can be caused by allergies to pollen, chemicals or drugs, and can also occur during menstruation, after strenuous exercise, and viral infections, and is generally of no importance. The diagnosis should be made by history, physical examination, laboratory tests and other auxiliary examinations, and after determining the true hematuria, the local diagnosis of hematuria should be made to distinguish whether it comes from the renal parenchyma or from the urinary tract.
①If tubular pattern, especially red blood cell tubular pattern, is found in the urine sediment, it indicates that the hemorrhage comes from the renal parenchyma;
② Hematuria with more severe proteinuria is almost always a sign of glomerular hematuria;
③If tubular patterns containing immunoglobulins are found in the urine, the hemorrhage is usually of renal parenchymal origin;
④The majority of red blood cells in hematuria caused by glomerular disorders are malformed, with different morphology and obvious size differences, whereas in non-glomerular hematuria, the majority of red blood cells are normal in size, and only a small number of them are malformed red blood cells.