Understanding Kidney Failure: Types, Causes, Symptoms, and Treatment

What is Kidney Failure

Kidney failure, also known as renal failure, occurs when the kidneys can no longer function effectively. This condition impairs the kidneys' ability to filter waste, excess fluids, and toxins from the bloodstream, leading to a dangerous buildup of these substances in the body. Individuals diagnosed with kidney failure have lost approximately 85% to 90% of their kidney function, severely affecting overall health.

Kidney failure can arise from either acute (sudden) or chronic causes. When considering chronic kidney failure, it is essential to note that it represents the final stage of chronic kidney disease.This condition Is medically referred to as advanced stage as end stage renal disease (ESRD) or end stage kidney disease (ESKD).

Physiology of the Kidneys

When blood flows to the kidneys, specialized kidney cells act as sensors to regulate how much water is excreted as urine, along with the concentration of electrolytes. This process ensures fluid balance in the body. If a person is dehydrated due to exercise or illness, the kidneys conserve water, making the urine more concentrated. Conversely, when there is an adequate water supply, the kidneys excrete more diluted urine. This function is controlled by renin, a hormone produced in the kidneys that plays a crucial role in fluid balance and blood pressure regulation

In addition to fluid regulation, the kidneys produce erythropoietin, a hormone responsible for stimulating the bone marrow to produce red blood cells. Specialized kidney cells monitor oxygen levels in the blood; if oxygen levels drop, erythropoietin production increases, prompting the body to generate more red blood cells.

Once urine is produced by the kidneys, it flows through the ureters (tubes connecting the kidneys to the bladder). The bladder stores urine until it is expelled through the urethra during urination. This continuous filtration and regulation process keeps the body’s internal environment stable and healthy.

Healthy kidneys are essential for cleaning the blood by removing excess fluids, minerals, and waste from the bloodstream. They also produce hormones that help maintain strong bones and support red blood cell production. When the kidneys are damaged, they fail to perform these functions effectively, leading to fluid retention, waste accumulation, high blood pressure, and insufficient RBC production – anemialeading to kidney failure

Causes of Kidney Failure

Kidney failure can arise from various causes, categorized into acute kidney failure (AKF)and chronic kidney disease (CKD).Each type has distinct causes and risk factors.

Causes of Acute Kidney Failure (AKF)

Acute kidney failure occurs suddenly and can result from conditions that impair kidney function. Common causes include:

• Kidney damage due to disease, infections, or exposure to toxins
• Dehydration, which reduces blood flow to the kidneys
• Physical trauma sustained from major surgery or accidents
• Blocked ureters, often due to kidney stones, tumors, or an enlarged prostate
• Sudden high blood pressurethat affects kidney function
• Inflammation affecting the kidneys
• Medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), certain antibiotics, diuretics, and ACE inhibitors, which can contribute to acute kidney failure

Causes of Chronic Kidney Disease (CKD)

Chronic kidney disease develops gradually over time, typically due to long-term conditions that impair kidney function. The most common causes include:

• Diabetes
• High blood pressure
• Glomerulonephritis
• Polycystic kidney disease
• Kidney infections, which can cause long-term damage if left untreated

Additional Causes and Risk Factors

Other conditions and factors that may contribute to kidney failure include:

• A blood clot in or around the kidneys
• Heavy metal poisoning, such as lead or mercury exposure
• Drug and alcohol use, which can lead to kidney toxicity
• Autoimmune diseases, such as lupus and scleroderma, which cause inflammation and damage to kidney tissue
• Vasculitis, an inflammation of the blood vessels that can affect kidney function
• Hemolytic uremic syndrome, a condition that leads to red blood cell breakdown, usually following a bacterial infection
• Multiple myeloma, a type of cancer that affects plasma cells in the bone marrow
• Thrombotic thrombocytopenic purpura (TTP), a rare disorder causing blood clots in small blood vessels
• Certain chemotherapy drugs, which may be toxic to the kidneys
• Dyes used in imaging tests, which can affect kidney function

Types of kidney failure

There are two primary types of kidney failure: acute and chronic. Each type has distinct characteristics and implications for treatment.

Acute Kidney Failure

Acute kidney failure (AKF), also known as acute kidney injury or acute renal failure,occurs suddenly, typically within a few hours or days. This condition can result from various factors, including infections, trauma to the kidney, or decreased blood flow. Additionally, blockages such as kidney stonesor very high blood pressurecan lead to acute kidney failure.

While AKF is potentially reversible with timely medical intervention, it can be life-threatening if left untreated. Studies indicate that approximately 12% to 15% of AKF patients may require long-term dialysis.

Chronic Kidney Failure (CKF)

Chronic kidney disease (CKD), also known as chronic renal failure or chronic renal disease, develops gradually over time and results in progressive kidney damage. Common contributing factors include diabetes, hypertension, and cardiovascular disease. In some cases, genetic predisposition also plays a role

CKD is diagnosed when kidney damage or an eGFR of less than 60 mL/min/1.73 m² persists for at least three months, regardless of the underlying cause. This progressive condition ultimately leads to the need for renal replacement therapy, such as dialysis or kidney transplantation. Understanding the differences between acute and chronic kidney failure is essential for effective management and improving patient outcomes. Early detection and intervention are critical in both cases to prevent complications and preserve kidney function

Stages of chronic kidney disease

Chronic kidney disease is classified into five stages ranging from very mild to complete loss of kidney function (kidney failure). Distinct symptoms and complications increase as the stages progress. Estimated glomerular filtration rate (eGFR) helps determine the stage of CKD as the condition progresses. The stages are as follows;

Signs & Symptoms of Kidney Failure

Kidney failure symptoms vary in severity and onset depending on whether it is acute kidney failure (AKF) or chronic kidney disease (CKD). AKF symptoms appear suddenly, while CKD symptoms develop gradually over time as kidney function declines.

General symptoms include;

Diagnostic Investigations & Test

Several tests to diagnose kidney failure. Common tests include:

• Urinalysis
• Urine volume measurements
• Blood urea nitrogen
• Creatinine
• Magnetic resonance imaging (MRI)
• CT scans
• Abdominal ultrasound
• Glomerular filtration rate (GFR)
• Kidney biopsy

Treatment of Kidney Failure

The treatment for kidney failure depends on the cause and stage of the condition, with prevention being the primary goal, especially for chronic diseases like hypertensionand diabetes

Once kidney failure is present, the goal is to prevent further decline in renal function. Addressing and aggressively treating underlying illnesses can help preserve kidney function, though improvement is not always possible

Medications

Various classes of medications may be used to manage issues associated with kidney failure:

• Phosphorus-lowering medications such as calcium carbonate (Caltrate), calcitriol (Rocaltrol), and sevelamer (Renagel)
• Red blood cell production stimulants: Including erythropoietin and darbepoetin (Aranesp)
• Iron supplements to support red blood cell production
• Blood pressure medications
• Vitamins

Once kidneys fail, treatment options are limited to dialysis or kidney transplantation

Dialysis

Dialysis filters and purifies the blood using a machine to perform the kidneys' function. Depending on the type of dialysis, patients may connect to a large machine or use a portable catheter bag. Patients may also need to follow a low potassium and low salt diet. While dialysis does not cure kidney failure, regular treatments can extend life. There are two main types of dialysis:

• Hemodialysis: Uses a machine to filter the blood, requiring regular sessions at a medical facility or home setup
• Peritoneal dialysis: Utilizes the abdominal lining to filter waste through a special fluid in a catheter-based process

Kidney Transplant

A kidney transplant can restore kidney function, eliminating the need for dialysis. However, there is often a long wait for a compatible donor kidney. If a living donor is available, the process may be expedited

Transplant surgery may not be suitable for everyone and is not always successful. Post-surgery, patients must take immunosuppressant drugs to prevent rejection of the new kidney, which can have serious side effects

Dietary Changes

Dietary modifications can help prevent the progression of kidney failure. Recommendations often vary based on the stage of kidney disease and overall health:

• Limiting potassium: Typically, up to 2,000 milligrams (mg) per day, but individual targets may vary
• Limiting sodium: Recommended intake is generally 2,000 to 2,300 mgdaily, with some experts suggesting 1,500 mg for those with CKD
• Limiting phosphorus: Aim to stay below 1,000 mg
• Following protein guidelines: May involve reducing protein intake in early and moderate kidney disease, while those on dialysis may need to increase protein consumption

Complications of Kidney Failure

When the kidneys fail to function or do not function properly, it affects the functions of other organs in the body as well. As kidney failure progresses, it results in several complications such as

• Heart disease
• High blood pressure
• Bone loss
• Anemia
• Bone weakness, due to an imbalance of phosphorus and calcium
• Hyperkalemia (high potassium levels)
• Metabolic acidosis (when blood becomes too acidic)

Secondary complications such as

• Gout
• Nerve damage
• Skin infections
• Depression
• Fluid buildup in the lungs
• Liver failure

Preventions of Kidney Failure

Certain measures may help decrease risk of developing kidney failure and include;

• Treating urinary tract infectionsto prevent kidney damage
• Limiting alcohol intake
• Avoiding or quitting smoking if you smoke
• Maintaining a healthy weight
• Exercising regularly
• Eating a balanced diet
• Treating conditions, such as diabetesand high blood pressure
• Limiting the use of certain medications, such as NSAIDs (ibuprofen and naproxen), antacids and high doses of vitamin C