Red blood cells (RBCs) are a component of blood. Their presence in urine, known as hematuria, is a medical sign that warrants attention. Hematuria is not a disease itself but a symptom that often signals an underlying condition requiring investigation.
Understanding Red Blood Cells in Urine
Red blood cells transport oxygen throughout the body. Normally, kidneys filter waste from blood, producing urine free of RBCs. Their appearance in urine suggests a leak or issue within the urinary tract, which includes the kidneys, ureters, bladder, and urethra.
Hematuria can manifest in two forms: microscopic and gross. Microscopic hematuria involves blood cells detectable only under a microscope, with the urine appearing normal to the naked eye. Gross hematuria is visible, causing the urine to appear pink, red, or brown, sometimes even containing small blood clots.
Common Causes
Various conditions can lead to the presence of red blood cells in urine, ranging from minor issues to more serious health concerns. Urinary tract infections (UTIs) are a frequent cause, where bacteria irritate and inflame the lining of the urinary tract, leading to small blood vessels rupturing and releasing blood into the urine. Symptoms like a strong urge to urinate, pain during urination, and cloudy urine often accompany UTIs.
Kidney stones, hard deposits formed from minerals in urine, can also cause hematuria. These stones may irritate or block the urinary tract, leading to bleeding, often accompanied by severe pain if they move or cause an obstruction. Kidney diseases, such as glomerulonephritis, involve inflammation of the tiny filters within the kidneys that can allow red blood cells to leak into the urine.
For men, prostate issues like benign prostatic hyperplasia (BPH), an enlargement of the prostate gland, can press on the urethra and lead to blood in the urine. Bladder conditions, including bladder infections (cystitis) and bladder cancer, are other potential sources of hematuria. Tumors in the bladder can also result in bleeding.
Certain medications, such as blood thinners like aspirin, heparin, or warfarin, can increase the likelihood of bleeding, including in the urinary tract. Some antibiotics and pain relievers may also contribute. Strenuous exercise, particularly activities like long-distance running or contact sports, can cause temporary hematuria due to bladder trauma or increased pressure on kidney filters, though this usually resolves quickly. Sometimes, despite thorough investigation, no specific cause is identified, a condition referred to as idiopathic hematuria.
When to Seek Medical Attention
Seek medical attention if red blood cells are detected in your urine, whether visible or not. Microscopic hematuria warrants medical evaluation to determine its underlying cause. Ignoring blood in urine, particularly gross hematuria, can delay the diagnosis of potentially serious conditions.
You should promptly consult a doctor if you observe visible blood in your urine, or if hematuria is accompanied by other symptoms. These symptoms can include pain during urination, frequent urination, difficulty urinating, or an urgent need to urinate. Additional concerning signs that necessitate immediate medical attention are fever, pain in the side or back (flank pain), or abdominal pain. Professional medical assessment is crucial for an accurate diagnosis and appropriate management.
Diagnostic Process and Management
To determine the cause of red blood cells in urine, a healthcare provider will typically begin with a thorough medical history and physical examination. Diagnostic tests often include a urinalysis, which confirms the presence of blood and checks for other substances or signs of infection. A urine culture may also be performed to identify bacterial infections.
Imaging studies provide detailed views of the urinary system. These can include ultrasounds, CT scans of the abdomen and pelvis (CT urography), or MRIs, which help detect structural issues, kidney stones, or tumors. For a closer look at the bladder and urethra, a cystoscopy may be conducted. This procedure involves inserting a thin, flexible tube with a camera into the urethra to visualize the internal lining. In some instances, a kidney biopsy might be necessary to diagnose specific kidney diseases.
Management of hematuria depends entirely on the identified underlying cause. For example, urinary tract infections are typically treated with antibiotics. Kidney stones may require pain management or urological procedures, such as lithotripsy or surgical removal. Kidney diseases may necessitate specialized treatments or referral to a nephrologist. If a serious condition like cancer is diagnosed, treatment will involve specific interventions like surgery, chemotherapy, or radiation therapy. Identifying the precise cause is important for effective treatment and to prevent potential complications.