Kidney stones are a common condition affecting the urinary system, characterized by hard deposits that form within the kidneys. These stones can cause a range of symptoms, and one of the most frequently observed is bleeding. While the presence of blood in urine can be unsettling, understanding its causes and manifestations is important for appropriate management.
How Kidney Stones Cause Bleeding
Kidney stones can lead to bleeding by physically interacting with the delicate tissues of the urinary tract. As stones form and grow, they may remain in the kidney without causing immediate issues. However, when a stone moves from the kidney into the ureter—the narrow tube connecting the kidney to the bladder—it can cause irritation and damage. This movement or lodging can scratch or abrade the inner lining of the urinary tract.
The urinary tract’s lining contains numerous small blood vessels. When irritated or damaged by the stone’s rough edges or movement, these blood vessels can rupture. This rupture releases blood into the urine, a phenomenon known as hematuria. In some cases, a stone blocking the urinary flow can lead to pressure buildup in the kidney, which may also cause tiny blood vessels to break.
Types of Bleeding
Bleeding associated with kidney stones can manifest in two primary ways: macroscopic hematuria and microscopic hematuria. Macroscopic hematuria, also known as gross hematuria, refers to visible blood in the urine. The urine might appear pink, red, or even a cola-like brown color due to the presence of blood. This visible change occurs even with a small amount of blood, as little as 1 milliliter per liter of urine.
Microscopic hematuria, conversely, is not detectable by the naked eye. Microscopic hematuria is typically identified through a urinalysis, a laboratory test where a urine sample is examined under a microscope to detect red blood cells. It is worth noting that the extent of bleeding does not always correlate with the size or severity of the kidney stone.
When to Seek Medical Attention
Any visible blood in the urine, regardless of whether kidney stones are suspected, warrants prompt medical evaluation. While kidney stones are a common cause, other conditions can also lead to hematuria.
Several accompanying symptoms, if experienced alongside potential kidney stone bleeding, necessitate immediate medical care. These include severe pain that makes it impossible to find a comfortable position, often described as colicky pain that comes in waves. Fever and chills are serious signs, potentially indicating an infection requiring urgent intervention. Nausea and vomiting, difficulty urinating, or a significant decrease in urine output are also indicators for immediate medical attention.