Hematuria is a medical problem, characterized by the presence of blood (specifically red blood cells or RBCs) in the urine. Based on the amount of blood excreted in the urine, hematuria is categorized into two types, namely, macroscopic (or gross) hematuria and microscopic hematuria. In the former case, the blood quantity is significantly high, thus changing the urine color to pink or red. Whereas in microscopic hematuria, the amount of blood present is relatively less, thus requiring microscopic analysis for detection of RBCs. Even though blood in the urine is mostly associated with pain, some patients do report unpainful hematuria or hematuria in absence of dysuria.
Causes and Symptoms of Painless Hematuria
Both painless and painful hematuria should be taken seriously, as they can be an indication of severe, life-threatening medical conditions like cancer, chronic kidney diseases, and infections. Very often, painful hematuria signifies kidney stones and infections, while the painless type may be associated with several other diseases that are related to kidney, bladder, and urinary system.
Glomerulonephritis: Almost all disorders related to glomerulus are accompanied with painless condition of hematuria. In addition to blood in urine, glomerulonephritis may also cause decrease in urine production and edema.
Arteriovenous Fistulas: Arteriovenous fistulas refers to abnormal accumulation of blood vessels in the kidney and other parts of the urinary system. Many times, arteriovenous fistulas is associated with bleeding, which in turn results in recurrent onset of hematuria with little or no pain.
Kidney Infections: Kidney infections (pyelonephritis) also cause hematuria without any pain. At times, inflammation of the kidney (nephritis) occurs without any known cause, which results in bloody urine.
Renal and Bladder Tumor: Majority of the patients with kidney cancer and/or bladder cancer exhibit blood in urine without any significant pain. Nevertheless, it is not the only symptom for presence of tumors in these organs. Considering this, thorough examination is necessary for evaluation of the condition.
Urinary Tract Cancer: Gross painless hematuria is a common sign of urinary tract cancer, both in men and women. Ultrasonography is usually recommended in order to locate the cancerous cells and identify the types of cells. Other noticeable symptoms of urinary tract cancer are frequent urination and enlarged lymph nodes.
Benign Prostatic Hypertrophy (BPH): Unpainful hematuria can also be resulted due to benign prostatic hypertrophy (BPH) that causes enlargement of the prostate. Other symptoms of BPH include general discomfort and inability to urinate.
Sickle Cell Disease: Patients of any form of sickle-cell disease experience painless hematuria. The doctor may conduct hemoglobin electrophoresis and/or sickle-cell preparation for confirming whether sickle-cell disease is the cause for presence of blood in urine or not.
Strenuous Exercise: Another reason for causing pain-free hematuria is strenuous exercise. If exercise is the sole cause for blood in urine, then the symptoms usually subside within two to three days. However, if hematuria is reported even after three days, the doctor may recommend further urologic evaluation.
Medications: Certain drugs and medications (antibiotics, analgesics, anticoagulants) may cause hematuria that is pain-free. In such a case, the doctor may prescribe alternatives for the current medicines, which are responsible for causing hematuria. Further urinalysis (after changing the medications) is necessary for checking the presence of blood in the urine.
In some cases, unpainful hematuria can be manifested as a result of urinary tract infections (UTI), renal papillary necrosis, kidney stones, and polycystic kidney disease. Depending upon the underlying cause, the hematuria can be a mild condition or a life-threatening problem.
Differential Diagnosis of Painless Hematuria
As there are several possible reasons for causing unpainful hematuria, complete investigation is always advisable to rule out serious health conditions. Correct identification of the root cause is also necessary, so that the doctor can decide appropriate medications (if necessary) and other treatment options. The best method for confirming the exact cause of bloody urine is differential diagnosis. Depending upon the medical history and physical examination of the patient, the doctor may recommend any of the following techniques for diagnosis of painless hematuria.
Dipstick Test: For patient with hematuria, dipstick analysis is usually performed to identify any case of urinary tract disorder. In this method, cellulose strips are used to check the amount of blood present in the urine. If the strip changes to dark green after dipping in the urine sample, then it indicates the presence of high amount of blood in the urine.
Imaging Tests: Computed tomography urography is the latest differential diagnostic method for hematuria. In this procedure, the entire urinary tract can be examined in one session. As for pediatric painless hematuria, the physician may perform other imaging tests that involve minimum exposure to radiation, such as ultrasound and intravenous pyelogram (IVP).
Urinalysis: Urinalysis involves checking the composition of urine. Presence of white blood cells along with red blood cells indicates urinary tract infections. Likewise, abnormalities in the urine composition helps in ruling out other health conditions. If infection in the urinary tract is suspected, urine culture is done to check for presence of bacteria and other pathogens.
Blood Test: Blood test is also a common diagnostic approach, which is performed for confirming the causes of hematuria without pain. If there is presence of wastes in the blood sample, then it signifies impairment of the kidney functionality. Thus, a blood test is useful for detecting kidney diseases.
Cystoscopy: Cystoscopy involves optical examination of the bladder with the help of a scope. In the procedure, a thin tube fixed with a tiny camera is introduced in the urethra and images of the bladder are taken. The images are examined carefully for making out abnormalities in the bladder.
Treatment of this painless condition depends upon the underlying cause and the diagnostic result. On a general note, cases of hematuria in children and adults are treated differently. It is also to be borne in mind that both painless and painful hematuria can occur without any specific reason. As per statistics, asymptomatic hematuria occurs in about 2.5 percent of the global population. Thus, a thorough painless hematuria workup can only reveal whether the current condition requires therapeutic intervention or not.