Kidney Disease – Causes, Symptoms, Treatments

What are Kidney Disease & Chronic Kidney Disease?

Kidney disease is a general term for a condition that damages your kidneys’ filtering capacity. Kidneys are two bean-shaped organs located near your lower back. They perform essential functions in maintaining overall health, including filtering waste products and excess fluid from your blood, regulating electrolyte balance (such as sodium, potassium, and calcium), controlling blood pressure, and even producing red blood cells.

Distinct from other forms of kidney disease, chronic kidney disease (CKD) is specifically characterized by a gradual and progressive decline in kidney function over an extended period, often months or even years. This progressive loss of function can eventually lead to end-stage renal disease (ESRD), where the kidneys can no longer function independently. At this stage, dialysis or a kidney transplant becomes necessary for survival.

Kidney disease is surprisingly prevalent. In the United States, it is estimated that more than 37 million adults have chronic kidney disease, which is 1 in 7 adults. However, as many as 9 in 10 adults with CKD do not know they have it. Chronic Kidney Disease is more common in people aged 65 years or older (34%) than in people aged 45 to 64 years (12%) or 18 to 44 years (6%).

This disease is also slightly more common in women (14%) than men (12%). Research also suggests that CKD is more common in non-Hispanic Black adults (20%) than in non-Hispanic Asian adults (14%) or non-Hispanic White adults (12%).

Differences Between Kidney Disease and Chronic Kidney Disease

Kidney disease can develop suddenly (acute) or gradually (chronic). It may or may not have symptoms in the early stages. In later stages, symptoms can include blood in the urine, high blood pressure, swelling, fatigue, and difficulty sleeping.

On the other hand, chronic kidney disease (CKD) develops slowly over an extended period. It often does not present itself in the early stages, with symptoms similar to general kidney disease appearing later as the condition progresses.

Treatment:

Kidney disease treatment depends on the underlying cause and can involve medication, lifestyle changes, or procedures to address the specific issue. Chronic kidney disease (CKD) treatment focuses on slowing the progression of CKD and preventing complications. This may involve managing underlying conditions like diabetes or high blood pressure, medication, dietary changes, and monitoring kidney function.

Kidney disease can range from mild and treatable to life-threatening. Chronic kidney disease (CKD) however, can lead to kidney failure (end-stage renal disease) if left unmanaged. Though early detection and treatment can significantly improve the prognosis.

Types of Kidney Diseases

Kidney disease is a general term for any condition that damages the kidneys and impedes their ability to function properly. There are numerous variations of kidney disease, ranging from mild to life-threatening. 

Diabetic nephropathy is the primary cause of kidney failure in diabetic patients. Chronically high blood sugar levels can damage the delicate blood vessels within the kidneys, leading to a gradual decline in function.

Glomeruli are microscopic filters within the kidneys responsible for waste removal from the blood. In glomerulonephritis, these filters become inflamed due to various factors, such as infections, autoimmune disorders, or certain medications. This inflammation disrupts the filtration process and hinders kidney function.

Polycystic kidney disease (PKD) is an inherited condition characterized by the growth of numerous cysts, or fluid-filled sacs, within the kidneys. These cysts can progressively enlarge, ultimately damaging surrounding healthy tissue and compromising kidney function.

Kidney stones are hard deposits formed within the kidneys, often composed of minerals and salts. While they may not cause any symptoms initially, kidney stones can cause excruciating pain, blood in the urine, and difficulty urinating when they move around or become lodged within the urinary tract.

Stages of Chronic Kidney Disease

Chronic kidney disease (CKD) is categorized into five stages, providing a roadmap for understanding the severity of kidney function decline. Two primary factors determine the CKD stage.

• Estimated glomerular filtration rate (eGFR): This blood test assesses your kidneys’ waste filtration efficiency. A lower eGFR indicates reduced kidney function.
• Urine albumin-to-creatinine ratio (UACR): This test measures the amount of albumin, a protein, in your urine. The presence of albumin in the urine can be a sign of kidney damage.

By combining the results of these two tests, healthcare professionals can determine the stage of CKD. Here’s a breakdown of the five stages:

• Stage 1: In this earliest stage, some evidence of kidney damage might be present. However, the eGFR is still within the normal or even slightly increased range (greater than 90 mL/min/1.73 m²).
• Stage 2: This stage indicates a mild reduction in kidney function, with an eGFR ranging from 60-89 mL/min/1.73 m².
• Stage 3:  This stage signifies moderate kidney function decline and is further categorized into 3a (45-59 mL/min/1.73 m²) and 3b (30-44 mL/min/1.73 m²) based on the severity of the eGFR reduction.
• Stage 4: This stage indicates a severe reduction in kidney function, with an eGFR ranging from 15-29 mL/min/1.73 m².
• Stage 5: This stage represents kidney failure, where the eGFR is less than 15 mL/min/1.73 m² or dialysis is necessary to support kidney function.

Symptoms of Chronic Kidney Disease

Chronic kidney disease (CKD) is often referred to as a “silent disease” because it can progress significantly without noticeable symptoms in the early stages. This emphasizes the importance of regular checkups and screenings, particularly for individuals with risk factors for CKD.

However, as CKD advances, various symptoms may begin to manifest. These can be a general indicator of declining kidney function and can serve as a wake-up call to seek medical attention. Here are some potential symptoms to be aware of.

Changes in urination can include urinating more often, especially at night, or less frequently than usual. You might also notice blood in your urine or foamy urine, which can be a sign of protein in the urine. The kidneys play a role in red blood cell production, which carry oxygen throughout the body. As CKD progresses, anemia can develop, leading to fatigue, weakness, and shortness of breath.

This condition can also disrupt the body’s hormonal balance, leading to nausea and a decreased appetite. Swollen ankles, feet, and hands are usually seen as a result of fluid retention due to the kidneys’ inability to effectively remove excess fluids from the body. CKD can also cause imbalances in minerals and electrolytes, leading to dry and itchy skin.

Various factors related to CKD, such as shortness of breath, restless legs syndrome, and the need to urinate frequently at night, can disrupt sleep patterns. Electrolyte imbalances associated with the disease also contribute to muscle cramps.

CKD and high blood pressure often go hand-in-hand, and each condition can worsen the other. In severe cases, the buildup of waste products in the blood due to impaired kidney function can affect brain function, leading to difficulty concentrating.

Symptoms of Kidney Disease

Kidney disease can progress significantly without noticeable symptoms in the early stages. This underscores the importance of regular checkups and screenings, especially for those with risk factors.

However, as kidney disease advances, various symptoms may develop. These can be a general indication of declining kidney function and a prompt to seek medical attention. 

• Changes in urination: This can include urinating more often, particularly at night (nocturia), or less frequently than usual. You might also notice blood in your urine (hematuria) or foamy urine, which can be a sign of protein in the urine (proteinuria).
• Fatigue and weakness: The kidneys play a role in red blood cell production, which carry oxygen throughout the body. As kidney disease progresses, anemia can develop, leading to fatigue, weakness, and shortness of breath.
• Loss of appetite and nausea: Kidney disease can disrupt the body’s hormonal balance, leading to nausea and a decreased appetite.
• Swollen ankles, feet, and hands: This is a result of fluid retention due to the kidneys’ inability to effectively remove excess fluids from the body (edema).
• Itchy and dry skin: Kidney disease can cause imbalances in minerals and electrolytes, leading to dry and itchy skin.
• Trouble sleeping: Various factors related to kidney disease, such as shortness of breath, restless legs syndrome, and the need to urinate frequently at night, can disrupt sleep patterns.
• Muscle cramps: Electrolyte imbalances associated with kidney disease can contribute to muscle cramps.
• High blood pressure: Kidney disease and high blood pressure often go hand-in-hand, and each condition can worsen the other.
• Difficulty concentrating: In severe cases, the buildup of waste products in the blood due to impaired kidney function can affect brain function, leading to difficulty concentrating.

Complications of Kidney Disease and Chronic Kidney Disease

While both kidney disease and chronic kidney disease (CKD) can lead to complications, the key difference lies in the severity and progression of these complications. Here’s a breakdown of how they differ:

Kidney Disease: Complications arising from kidney disease can vary depending on the underlying cause and the severity of the condition.

• Acute kidney injury: This is a sudden and rapid decline in kidney function. It can lead to electrolyte imbalances, fluid overload in the lungs (pulmonary edema), and even complete kidney failure requiring dialysis.
  
• Chronic, uncontrolled kidney disease: Left untreated, any form of kidney disease can progress and eventually lead to complications like:
  
  • High blood pressure: Damaged kidneys struggle to regulate blood pressure, and high blood pressure can further worsen kidney function.
  • Cardiovascular disease: Kidney disease is a significant risk factor for heart disease and stroke.
  • Anemia: Reduced kidney function can impair red blood cell production, leading to anemia and its associated symptoms like fatigue and shortness of breath.

Chronic Kidney Disease (CKD): CKD is a progressive condition, meaning the complications tend to worsen over time as kidney function continues to decline. Here are some of the potential complications associated with different stages of CKD:

• Early stages (1-3): In these stages, complications may be minimal. However, high blood pressure and early signs of anemia can be present.
  
• Later stages (4-5): As CKD progresses, complications become more frequent and severe. These may include:
  
  • Bone mineral disease: Healthy kidneys play a crucial role in maintaining the balance of calcium, phosphorus, and other minerals in the blood. In CKD, this balance can become disrupted. High phosphorus levels can weaken bones and increase the risk of fractures, while imbalances in calcium and other minerals can contribute to problems with bone health and parathyroid hormone function.
  • Weakened immune system: Individuals with CKD are more susceptible to infections.
  • Peripheral neuropathy: Nerve damage in the hands and feet can cause numbness, pain, and weakness.
  • Heart failure: Chronic fluid overload and electrolyte imbalances can strain the heart and lead to heart failure.
  • Uremia: This is a buildup of waste products in the blood due to impaired kidney function. It can cause a variety of symptoms like fatigue, nausea, and difficulty concentrating.
• End-stage renal disease (ESRD): This is the most severe complication of CKD, where the kidneys can no longer function independently. Dialysis or a kidney transplant becomes necessary for survival.

. Here are some potential complications of CKD:

• Cardiovascular disease: CKD is a significant risk factor for heart disease and stroke. Reduced kidney function can contribute to high blood pressure, unhealthy cholesterol levels, and inflammation in the body, all of which increase the risk of cardiovascular complications.
• Anemia: As CKD progresses, the kidneys become less efficient in producing erythropoietin, a hormone that stimulates red blood cell production. This can lead to anemia, a condition characterized by a lack of red blood cells, resulting in fatigue, weakness, and shortness of breath.
• Mineral and bone disorder: Healthy kidneys play a crucial role in maintaining the balance of calcium, phosphorus, and other minerals in the blood. In CKD, this balance can become disrupted. High phosphorus levels can weaken bones and increase the risk of fractures, while imbalances in calcium and other minerals can contribute to problems with bone health and parathyroid hormone function.
• High blood pressure: CKD and high blood pressure can form a vicious cycle. Damaged kidneys can struggle to regulate blood pressure, and high blood pressure can further worsen kidney function.
• Fluid overload: The kidneys are responsible for removing excess fluids from the body. When CKD progresses, the body may retain fluids, leading to swelling in the ankles, feet, and hands, as well as shortness of breath.
• Weakened immune system: A compromised immune system makes individuals with CKD more susceptible to infections.
• Neurological problems: In severe cases, the buildup of waste products in the blood due to impaired kidney function can affect brain function, potentially leading to difficulty concentrating, confusion, and even seizures.
• Nutritional problems: CKD can affect how the body absorbs and utilizes nutrients from food. Individuals with CKD may need to follow specific dietary restrictions to manage their condition.
• Kidney failure: This is the most severe complication of CKD, where the kidneys can no longer function independently. Dialysis or a kidney transplant becomes necessary for survival at this stage.

How are Kidney Disease and Chronic Kidney Disease Diagnosed?

Detecting and diagnosing kidney disease and chronic kidney disease (CKD) often involve a multi-step approach. Healthcare professionals typically utilize a combination of tests and examinations to assess kidney function and identify any underlying issues.

Doctors will inquire about your symptoms, medical history, risk factors for kidney disease (such as diabetes or high blood pressure), and any medications you’re taking. A physical examination may also be performed to check for signs of high blood pressure, swelling in the ankles or feet, and other potential indicators of kidney problems.

Urinalysis is a common test that analyzes the composition of your urine. It can detect the presence of blood, protein, or other abnormalities that might suggest kidney dysfunction. Another test might measure the urine albumin-to-creatinine ratio (UACR). An elevated UACR can be a sign of early kidney damage.

Blood tests play a crucial role in diagnosing kidney disease. They can assess kidney function by measuring the estimated glomerular filtration rate (eGFR). The eGFR is an estimate of how well your kidneys are filtering waste products from your blood. Lower eGFR values indicate reduced kidney function. Blood tests can also evaluate electrolyte levels, check for anemia (a condition associated with CKD), and assess other factors that might be affecting your kidneys.

In some cases, imaging tests like ultrasounds, CT scans, or MRI scans might be used to visualize the kidneys and identify any abnormalities in their size, structure, or presence of blockages.

How are Kidney Disease and Chronic Kidney Disease Treated?

Chronic kidney disease (CKD) and general kidney disease require different treatment approaches because they have distinct goals. Here’s a closer look:

Chronic Kidney Disease (CKD):

When it comes to CKD, the main objectives of treatment are to:

• Slow the decline in kidney function: The primary aim is to manage and decelerate the rate at which kidney function worsens. This helps to postpone reaching end-stage renal disease (ESRD), where dialysis or a kidney transplant becomes necessary for survival.
• Prevent and manage complications: CKD treatment proactively addresses potential complications such as high blood pressure, heart disease, bone issues, and anemia. By managing these complications, the aim is to delay their onset and minimize their impact on overall health.
• Improve quality of life: Effective CKD management aims to improve and maintain a good quality of life for patients. This means living longer, healthier lives with minimal disruption to daily activities.

To achieve these goals, various approaches are used:

• Medications: Certain medications play a crucial role. Blood pressure control medications, like ACE inhibitors or ARBs, are essential to manage blood pressure and slow down kidney function decline. Additionally, medications may be prescribed to manage cholesterol, anemia, and bone mineral disease, all of which can be associated with CKD.
• Dietary changes: A specialized diet may be recommended by a healthcare professional. This might involve limiting protein intake, managing electrolytes like phosphorus and potassium, and controlling blood pressure through dietary modifications.
• Lifestyle modifications: Maintaining a healthy weight, engaging in regular physical activity, quitting smoking, and getting adequate sleep are all essential for overall health and kidney function.
• Monitoring and managing underlying conditions: If another condition, such as diabetes, is contributing to CKD, effectively managing that underlying condition is crucial for CKD treatment success.
• Dialysis or kidney transplant (in later stages): If CKD progresses to ESRD, dialysis (a process to remove waste products from the blood) or a kidney transplant may be necessary to support kidney function.

Kidney Disease:

The goals of treatment for general kidney disease differ from those of CKD. Here’s what treatment aims to achieve:

• Address the underlying cause: The primary focus is to treat the specific root cause of the kidney disease, such as an infection, autoimmune disorder, or blockage in the urinary tract.
• Restore kidney function (if possible): In some cases, early intervention and treatment of the underlying cause can potentially reverse or halt the progression of kidney disease. In some instances, it might even be possible to restore kidney function to some degree.
• Prevent further damage: Treatment aims to prevent further deterioration of the kidneys and minimize the risk of complications arising from the condition.
• Manage symptoms: Depending on the type and severity of kidney disease, treatment may focus on managing symptoms. This could involve controlling pain, reducing blood pressure, or addressing fluid retention.

The approaches to treatment for general kidney disease also differ:

• Medications: The specific medications used will depend on the underlying cause of the kidney disease. For instance, antibiotics might be prescribed for infections, corticosteroids for autoimmune disorders, or pain relievers to manage discomfort.
• Procedures: Minimally invasive procedures like removing kidney stones or repairing urinary tract blockages might be necessary in some cases to address the underlying cause.
• Lifestyle modifications: Similar to CKD, maintaining a healthy weight, regular physical activity, and a healthy diet can support overall health and potentially aid in recovery from kidney disease.
• Dialysis or kidney transplant (in severe cases): If the kidney disease is severe and leads to kidney failure, dialysis or a transplant may be required.

What Medications are Most Often Prescribed for Kidney Disease & Chronic Kidney Disease?

While there isn’t a single medication universally prescribed for all kidney diseases and chronic kidney disease (CKD), several medication classes play a vital role in managing these conditions. 

1. Blood Pressure Control Medications:
   • Angiotensin-converting enzyme (ACE) inhibitors: These medications like lisinopril, enalapril, and ramipril help relax blood vessels, lowering blood pressure and reducing strain on the kidneys. They are particularly beneficial for individuals with CKD as they can slow the progression of the disease.
   • Angiotensin receptor blockers (ARBs): Similar to ACE inhibitors, ARBs (losartan, valsartan) work by blocking the effects of a hormone that constricts blood vessels, leading to lower blood pressure and reduced pressure on the kidneys.
2. Medications for Diabetes Management:
   • Blood sugar control medications: If diabetes is the underlying cause of kidney disease, medications like metformin or other blood sugar-lowering drugs can help manage blood sugar levels and potentially slow down kidney damage.
3. Diuretics:
   • Water pills: Diuretics like hydrochlorothiazide can help remove excess fluids from the body by increasing urine output. This can be beneficial for managing high blood pressure and fluid retention sometimes associated with kidney disease.
4. Phosphate Binders:
   • Certain medications: In CKD, the body may struggle to eliminate phosphorus, a mineral found in food. Phosphate binders (sevelamer carbonate, lanthanum carbonate) can help bind dietary phosphorus in the digestive system, preventing its absorption into the bloodstream.
5. Erythropoietin-Stimulating Agents (ESAs):
   • Anemia management: In some cases, CKD can lead to anemia. ESAs (epoetin alfa, darbepoetin alfa) are synthetic hormones that stimulate the bone marrow to produce more red blood cells, potentially improving symptoms of anemia like fatigue and weakness.
6. Medications for Bone Health:
   • Calcium and Vitamin D supplements: CKD can affect bone health. Calcium and vitamin D supplements may be prescribed to improve bone mineral density and reduce the risk of fractures.