The kidneys are involved in filtering the blood and concentrating this filtrate into urine. Urine is then typically expelled through tubes called the ureters into the bladder, where it can be excreted from the body. The ureters usually have valves to prevent urine from escaping the bladder and going back to the kidney and causing a condition known as renal reflux (also known as vesicoureteral reflux) . However, sometimes the ureters are abnormal and this reflux can occur.
In Adults
In adults, the most common symptom of renal reflux isa urinary tract infection. This occurs because the bacteria that cause the urinary tract infection are able to travel up the urinary tract as a result of the reflux instead of being pushed out during urination. As a result, patients may feel a sudden urge to urinate, and when urination does occur there is often a burning sensation. Other patients may feel the need to urinate frequently but only pass small amounts of urine. In some cases the urine may be mixed with blood or be cloudy and have a strong smell. Finally, some patients will develop a fever or have pain in their flank or lower back resulting from urine refluxing up to the kidneys.
In Infants
Often renal reflux problems begin during infancy as a result of unusually formed ureters. Early on the symptoms of renal reflux are infections of the urinary tract. However, because infants cannot speak, they can be difficult to diagnose. Infants with renal reflux disease often have stunted growth (clinically known as "failure to thrive"). They may also suffer from gastrointestinal problems, such as vomiting and diarrhea. In addition, they may be abnormally lethargic and have little or no appetite.
Advanced Symptoms
If renal reflux goes untreated, it can cause permanent damage to the kidneys. One sign of this may be the presence of protein in the urine, which can be detected on lab tests (and which can also cause increased urination). Some patients (particularly children) have trouble with wetting the bed. Because the kidneys are important for blood pressure control, kidney damage caused by renal reflux can lead to high blood pressure in children who otherwise would be at low risk for hypertension. Finally, long-standing renal reflux can cause kidney failure, which results in massive urine output as well as severe sickness as toxins build up in the blood.
