Hematuria (synonyms: erythrocyturia; essential hematuria; hematuria; hematuria (blood in urine); macrohematuria; mass hematuria; microhematuria; cystitic hematuria; hematuresis; ICD-10-GM R31: unspecified hematuria) refers to the presence of blood in urine. The following forms of hematuria are distinguished:
- Excretion of erythrocytes (red blood cells, more than 130,000 per 24 hours); corresponds to classic hematuria
- Excretion of hemoglobin (red blood pigment); also called hemoglobinuria (e.g., paroxysmal nocturnal hemoglobinuria, Marchiafava-Micheli; ICD-10-GM D59.5: Paroxysmal nocturnal hemoglobinuria [Marchiafava-Micheli])
Hematuria is further divided into:
- Microhematuria (synonyms: asymptomatic hematuria; non-visible hematuria) – more than 3,000 erythrocytes are excreted per minute with the primary urine; in this form, no discoloration of the urine is seen with the naked eye; only by means of urine strip test or microscopic image erythrocytes are noticed (> 5 erythrocytes/μl urine).
- Macrohematuria – in this form you can see a red coloration of the urine with the naked eye.
Microhematuria is usually an incidental finding during a routine examination (= asymptomatic microhematuria, AMH), macrohematuria usually leads the patient directly to the doctor. Hematuria can be a symptom of many diseases (see under “Differential diagnoses”). Frequency Peak: In a large study, the mean age for patients with asymptomatic hematuria was reported to be 48.2 years. The prevalence (disease incidence) of asymptomatic microhematuria ranges from 2.5% to 20% in adults. These often turn out negative after control examination. Course and prognosis: Hematuria should be understood as a warning signal. Diagnostic workup is required. Any hematuria must be assumed to be malignant (malignant) until proven otherwise. This applies in particular from the age of 40 and the presence of at least one risk factor (e.g., tobacco smoking, repeatedly detected microhematuria) and from the age of 50 without the presence of a risk factor. Asymptomatic hematuria may be indicative of malignancies (cancers) in the urinary tract (bladder carcinoma/upper tract urothelial carcinoma (UTUC)/renal cell carcinoma). In patients older than 40 years, diseases such as renal insufficiency (process leading to a slowly progressive reduction in kidney function) as well as hypertension (high blood pressure) and/or proteinuria (increased excretion of protein with the urine) must also be ruled out.However, in most cases no cause can be detected. This is especially the case in young people. The hematuria is then temporary and harmless. Risk factors, in the presence of which malignant (malignant) tumors occurred significantly more often are: Age, male gender, irritative symptoms during urination and smoking. One in three patients with macrohematuria has cancer. In most cases, patients are older than 70 years. In the majority of cases, urothelial carcinoma is present. The second most common diagnosis is prostate carcinoma. Notice:
- In a prospective observational study, 3.5 percent of patients with macrohematuria and a cancer diagnosis were younger than 45 years. 1 percent of cancer patients with microhematuria were younger than 60 years.
- Patients aged 70 years or younger with anticoagulation for atrial fibrillation who had macrohematuria had a 36.3-fold increased risk of urinary tract cancer compared with patients of the same age without hemorrhage.
An emergency exists when there is massive, anemic macrohematuria with coagulation (blood clot formation) and urinary bladder tamponade (filling of the urinary bladder with blood coagula). Such a patient should be admitted to the hospital immediately after placement of a large-lumen catheter (optimal: double-lumen irrigation catheter) and intravenous access.
