The kidneys are two bean-shaped organs, each about the size of a fist, located just below the rib cage on either side of the spine. Their primary function involves filtering approximately 150-180 quarts of blood daily, removing waste products and excess water to produce urine. Beyond waste removal, kidneys help regulate blood pressure, maintain fluid and electrolyte balance, and produce hormones that support red blood cell production and bone health. When these functions are impaired by disease, the body’s overall health can be significantly impacted.
Understanding Kidney Disease
Kidney disease refers to conditions where the kidneys are damaged or lose their ability to function properly. This impairment can range in severity, from mild dysfunction to complete kidney failure. There are two primary classifications for kidney disease based on how quickly the condition develops.
Acute Kidney Injury (AKI) involves a sudden decline in kidney function, often developing within hours or days. This sudden onset can be triggered by events like severe infections, significant blood loss, or certain medications. In many cases, AKI is reversible with prompt treatment of the underlying cause.
Chronic Kidney Disease (CKD), in contrast, is a long-term condition where kidney function gradually declines over months or years. CKD often progresses slowly, and symptoms may not appear until the disease is advanced. While treatment can slow the progression of CKD, it is generally considered irreversible and may eventually lead to end-stage renal disease, requiring dialysis or a kidney transplant.
Common Kidney Diseases
Chronic Kidney Disease (CKD) involves progressive kidney damage over at least three months, impairing waste filtration and balance. This gradual deterioration can lead to toxin buildup and increased risk of heart disease. Early stages often have no noticeable symptoms, with diagnosis typically occurring through routine tests.
Acute Kidney Injury (AKI) is a sudden decline in kidney function, developing within hours or days. It can result from reduced blood flow due to severe dehydration, heart failure, or certain medications like NSAIDs. Direct kidney damage from infections, toxins, or inflammation (glomerulonephritis), or urinary tract blockages, can also cause AKI.
Kidney Stones are hard deposits of minerals and salts that form inside the kidneys. Smaller stones may pass unnoticed, but larger ones can block urine flow in the ureters, causing intense pain in the back, side, or lower abdomen. Symptoms can include nausea, vomiting, blood in the urine, and painful urination.
Glomerulonephritis involves inflammation and damage to the glomeruli, the tiny filtering units within the kidneys. This impairs waste and fluid removal, leading to their accumulation. Causes include infections, autoimmune disorders like lupus, or certain toxins and medications. Symptoms may include blood or protein in the urine, swelling, fatigue, and high blood pressure.
Polycystic Kidney Disease (PKD) is an inherited genetic disorder causing fluid-filled cysts to grow in the kidneys. These cysts can significantly enlarge the kidneys and impair their function. PKD may also cause cysts in other organs, leading to complications like high blood pressure, headaches, and kidney stones.
Kidney Cancer develops when kidney cells grow uncontrollably, forming a tumor. Renal cell carcinoma (RCC) is the most common type. Early stages often have no symptoms and may be discovered incidentally. As the tumor grows, symptoms can include blood in the urine, a lump or mass, persistent side or back pain, and unexplained weight loss or fatigue.
Uncontrolled diabetes, or diabetic nephropathy, is a significant cause of CKD. High blood sugar levels over time damage the tiny blood vessels and filtering units in the kidneys. This impairs the kidney’s filtration process.
High blood pressure (hypertension) can also lead to kidney damage, known as hypertensive nephropathy. Chronic high blood pressure strains and narrows small blood vessels in the kidneys, reducing blood flow. This can result in hardening and thickening of kidney tissue, damaging the filtering units.
General Signs of Kidney Problems
When kidneys are not functioning optimally, several general signs may appear, indicating a need for medical evaluation. Swelling, known as edema, often occurs in the legs, ankles, feet, or even around the eyes, due to the kidneys’ inability to properly remove excess fluid and sodium from the body. Changes in urination patterns are also common, such as needing to urinate more frequently, especially at night, or noticing foamy, bubbly, or unusually colored urine.
Persistent fatigue, weakness, and difficulty concentrating can arise as toxins build up in the blood when the kidneys fail to filter them out efficiently. A lack of a hormone called erythropoietin, normally produced by healthy kidneys, can also lead to anemia, further contributing to tiredness and shortness of breath. Additionally, muscle cramps, appetite loss, nausea, and dry, itchy skin may signal kidney dysfunction, often due to imbalances in minerals and waste products in the blood.
Risk Factors for Kidney Disease
Several factors can increase an individual’s susceptibility to kidney disease. Diabetes (Type 1 and Type 2) and uncontrolled high blood pressure are leading causes. These conditions can damage the delicate blood vessels and filtering units within the kidneys over time.
A family history of kidney disease also increases one’s risk, suggesting a genetic predisposition. Obesity contributes to kidney disease risk by increasing the likelihood of developing diabetes and high blood pressure. Heart disease, including heart failure, can reduce blood flow to the kidneys, impacting their health. Other factors include smoking, which damages blood vessels throughout the body, and the prolonged use of certain medications, such as some non-steroidal anti-inflammatory drugs (NSAIDs), which can have a detrimental effect on kidney function.