Hematuria, the medical term for blood in the urine, can be a startling observation. This blood may be visible (gross hematuria) or only detectable under a microscope (microscopic hematuria). While hematuria can be caused by a wide range of issues, it always warrants immediate medical investigation. Hematuria can signal anything from a minor irritation to a serious underlying health condition, including a sexually transmitted infection.
Sexually Transmitted Infections That Cause Urethral Bleeding
Certain sexually transmitted infections (STIs) can directly cause blood in the urine by triggering inflammation in the urinary tract. Gonorrhea and Chlamydia are the most common STI culprits for this symptom. These bacteria primarily target the urethra, the tube that carries urine out of the body, leading to a condition called urethritis.
The inflammation irritates the delicate lining of the urethra. This irritation can weaken small blood vessels, causing minor bleeding that mixes with the urine. Hematuria caused by these STIs is often minor and microscopic, but it can sometimes be visible if the inflammation is severe or has spread to the prostate gland in men. Other STIs, such as Trichomoniasis, can also cause urinary tract inflammation that may result in blood in the urine, though this is less frequent.
Common Non-STD Infectious Causes of Hematuria
Infectious causes of blood in the urine are not limited to STIs. Urinary Tract Infections (UTIs) are the most common cause of hematuria across many populations and are typically not sexually transmitted. A UTI occurs when bacteria enter the urethra and multiply in the bladder, leading to inflammation of the bladder lining, known as cystitis.
This inflammation causes the bladder lining to become fragile, resulting in the release of red blood cells into the urine. If the infection is left untreated, bacteria can ascend from the bladder up the ureters to the kidneys, causing a more serious condition called pyelonephritis. A kidney infection often results in pronounced symptoms, including back pain, fever, and nausea, and can lead to more significant bleeding.
Serious Non-Infectious Explanations for Blood in Urine
Beyond infectious diseases, several non-infectious conditions can cause blood to appear in the urine, some of which carry a significant health risk. Kidney stones, which are hard deposits, can cause bleeding as they move through the urinary tract. The sharp edges of these stones can traumatize the lining of the ureters or bladder, resulting in blood mixing with the urine.
Physical trauma to the urinary system, such as from contact sports or an accident, can also cause bleeding from the kidneys or bladder. More serious underlying conditions include various cancers of the urinary tract, such as bladder, kidney, and prostate cancer. Hematuria can be an early, sometimes the only, symptom of these malignancies, which is why any instance of blood in the urine must be thoroughly investigated. Temporary causes, like intense exercise or the use of certain medications, can also lead to short-term hematuria.
When to Seek Testing and Medical Care
Any instance of blood in the urine, whether visible or only detected through a laboratory test, requires prompt evaluation by a healthcare provider. The initial diagnostic process begins with a thorough physical examination and a detailed medical history review, including questions about sexual activity and risk factors. A urinalysis is performed to confirm the presence of red blood cells and check for signs of infection, such as white blood cells or bacteria.
If an infection is suspected, urine cultures and specific nucleic acid amplification tests (NAATs) are used to check for common STIs like Chlamydia and Gonorrhea. Depending on the patient’s age and risk factors, the medical workup may proceed to imaging tests, such as an ultrasound or CT scan. These tests look for stones, tumors, or other structural issues in the kidneys and bladder. Patients must be transparent about their sexual history to ensure the correct tests are ordered and a proper diagnosis is reached swiftly.