Common Renal Disease

The term “renal” pertains to the kidneys. It is derived from the Latin word “ renalis,” which
is derived from “renes,” which means “kidneys.” Anything related to or involving the kidneys
is referred to as “renal.” For example, renal function refers to how well the kidneys are
working, and renal failure indicates the kidneys’ inability to function properly.
Renal Disease: Renal disease refers to any condition that impairs the normal function of the
kidneys. It can range from mild disorders, like infections or small kidney stones, to more
severe conditions, such as chronic kidney disease (CKD) or acute kidney injury (AKI). Renal
disease can be acute (sudden onset and potentially reversible) or chronic (long-term,
progressive, and often irreversible).

Units Related to Renal Function:

1. Glomerular Filtration Rate (GFR):
• Unit: milliliters per minute (mL/min)
• Description: GFR measures how much blood is filtered by the glomeruli (tiny
filters) in the kidneys per minute. It is an important indicator of kidney function.
2. Creatinine Clearance:
• Unit: milliliters per minute (mL/min)
• Description: This test measures the rate at which creatinine is cleared from the
blood by the kidneys, providing an estimate of GFR.
3. Blood Urea Nitrogen (BUN):
• Unit: milligrams per deciliter (mg/dL)
• Description: BUN indicates the amount of urea nitrogen in the blood, which is a
waste product that kidneys filter out.
4. Serum Creatinine:
• Unit: milligrams per deciliter (mg/dL)
• Description: Measures the amount of creatinine in the blood. Higher levels can
indicate reduced kidney function.
5. Electrolytes (e.g., Sodium, Potassium, Calcium):
• Unit: milliequivalents per liter (mEq/L) or milligrams per deciliter (mg/dL)
depending on the electrolyte
• Description: Electrolyte balance is crucial for kidney function, and imbalances
can be a sign of renal disease.

Renal disease is defined as a significant loss of renal function in both kidneys to

the point where less than 10 to 20% of normal GFR remains. Renal failure may
occur as an acute and rapidly progressing process or may present as a chronic form
in which there is a progressive loss of renal function over a number of years. Acute
renal failure has an abrupt onset and is potentially reversible. Chronic failure
progresses slowly over at least three months and can lead to permanent renal
failure.

Blood Urea Nitrogen (BUN)

The blood urea nitrogen (BUN) test measures the amount of urea nitrogen in the
blood. Urea nitrogen only reflects the nitrogen component of urea and not the
whole urea molecule. In healthy individuals, normal BUN levels range between 5
to 20 mg/dL or 1.8 to 7.1 mmol/L.

SERUM K, Na :

Potassium :
Stone formers often have a low to normal potassium intake and high sodium intake
that results in an adversely raised Na:K ratio. Every 20 mEq/day increase in
urinary potassium is associated with a 17 mg/day decrease in urinary calcium .

Sodium :
The daily amount of sodium chloride in modern diets reaches excessive levels of
up to 10 g/day.
The amount of sodium in the urine and hypercalciuria are correlated directly
because sodium and calcium are reabsorbed at common sites in the renal tubule.

CREATININE :
The kidneys maintain the blood creatinine in a normal range. Creatinine is a fairly
reliable indicator of kidney function. Elevated creatinine level signifies impaired
kidney function or kidney disease.
Normal levels of creatinine in the blood are approximately 0.6 to 1.2 milligrams
(mg) per deciliter (dL) .

Albuminuria :
Albuminuria refers to the abnormal presence of albumin in the urine.
Urine albumin may be measured in 24-hour urine collections or early
morning/random specimens as an albumin/creatinine ratio.

Renal function tests (RFT) are a group of tests that may be performed together to
evaluate kidney (renal) function. The tests measure levels of various substances,
including several minerals, electrolytes, proteins, and glucose (sugar), in the blood
to determine the current health of the kidneys.

Glomerular filtration rate (GFR) is a test used to check how well the kidneys are
working. Specifically, it estimates how much blood passes through the glomeruli
each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the
blood.
Normal blood parameters for diagnosis in kidney diseases.
Blood Parameters Normal Range
BUN (Blood Urea Nitrogen) 7-22 mg %
Creatinine 0.8-1.8 mg%
Uric acid 2.4-7.0 mg %
Sodium 132-148 mEq/L
Potassium 3.5-5.5 mEq/L
Phosphorus 3.0-4.5 mg %
Calcium 8.1-10.4 mg %
Chloride 98-108 mEq/L
Total protein 6.6-8.7 gm %
Albumin 3.8-4.4 gm%
Globulin 1.8-3.6 gm%
A/G ratio 2:1
Urine Electrolytes:
Chloride 110-250 mEq
Sodium 15-250 mEq /L
Potassium 25-120 mEq/L
Magnesium Less than 150 mg/day
Calcium 100-300 mg
Creatinine 1.1-3.4 g 1.1-3.4 g
Creatine Little or non

Table represents the general normal blood parameters for diagnosis in kidney diseases.
However, the levels depends on the local laboratory reference values

Reference:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2023). “Kidney
Function Tests.” Retrieved from https://www.niddk.nih.gov.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2023). “Kidney
Function Tests.” Retrieved from https://www.niddk.nih.gov.
Renal diseases encompass a variety of conditions that affect the kidneys, which play a crucial
role in maintaining homeostasis by filtering blood, removing waste, and regulating fluid
balance. Among the most common renal disorders are glomerulonephritis, nephrosis, chronic
kidney disease (CKD), and renal calculi. Chronic kidney disease, in particular, is a
progressive condition characterized by a gradual decline in the kidneys’ ability to function
effectively. CKD is classified into five stages based on the glomerular filtration rate (GFR),
which measures how well the kidneys are filtering blood. Early detection and management of
renal diseases are essential to prevent complications and maintain overall health.

Reference :
National Kidney Foundation. (2020). “Chronic Kidney Disease (CKD) Basics.”
https://www.kidney.org.
Signs and Symptoms of Renal Disease:

1. Edema (Swelling): Swelling in the legs, ankles, feet, face, or hands due to fluid retention.
This happens because the kidneys are not able to remove excess water and salt from the body
efficiently.
2. Changes in Urination:
 Frequency: Increased or decreased urination, particularly at night (nocturia).
 Appearance: Urine may be foamy (indicating proteinuria), bloody (hematuria),
or dark-colored.
 Amount: Decreased urine output despite adequate fluid intake.
3. Fatigue: A common symptom caused by anemia (reduced red blood cell production due to
decreased erythropoietin from the kidneys) or the buildup of toxins in the blood.
4. Nausea and Vomiting: Accumulation of waste products (uremia) in the bloodstream can
lead to gastrointestinal disturbances, including nausea, vomiting, and a loss of appetite.
5. Shortness of Breath: Fluid overload can lead to accumulation in the lungs (pulmonary
edema), causing difficulty in breathing.
6. Hypertension (High Blood Pressure): The kidneys play a role in regulating blood pressure.
Impaired function can lead to elevated blood pressure, which can further damage the kidneys.
7. Muscle Cramps: Electrolyte imbalances, especially involving potassium, calcium, and
phosphorus, can cause muscle cramps and twitching.
8. Itching: Uremic toxins can accumulate under the skin, causing persistent itching (pruritus).
9. Metallic Taste in the Mouth and Bad Breath: A buildup of toxins can cause a metallic taste
in the mouth and ammonia-like odor (uremic fetor) due to the breakdown of urea into
ammonia in saliva.
10. Cognitive Issues: Difficulty concentrating, memory loss, and confusion due to the effects
of uremia on the brain.

Reference:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2023).
“Symptoms & Causes of Kidney Disease.” https://www.niddk.nih.gov.

Causes of Renal Disease:

1. Diabetes Mellitus: The most common cause of chronic kidney disease (CKD). High
blood sugar levels over time can damage the blood vessels in the kidneys, reducing
their ability to filter waste and excess fluids from the blood.
2. Hypertension (High Blood Pressure): Elevated blood pressure can damage the small
blood vessels in the kidneys, impairing their function. It is both a cause and a
consequence of kidney disease, leading to a vicious cycle of progressive damage.
3. Glomerulonephritis: Inflammation of the glomeruli, the tiny filters in the kidneys.
It can be caused by infections, autoimmune diseases, or systemic illnesses.
Conditions like lupus nephritis fall under this category.
4. Polycystic Kidney Disease (PKD): A genetic disorder characterized by the growth
of numerous cysts in the kidneys. These cysts can enlarge the kidneys and reduce
their function over time.
5. Recurrent Urinary Tract Infections (UTIs): Chronic or recurrent infections can lead
to scarring of the kidneys (reflux nephropathy) and increase the risk of chronic kidney
disease.
 6. Kidney Stones Renal calculi : Stones can block the urinary tract and cause
infections, damage,
and ultimately lead to kidney function loss if left untreated.
7. Obstructive Conditions: Conditions such as enlarged prostate, kidney stones, or
tumors that block the flow of urine can lead to increased pressure in the kidneys,
causing damage.
8. Drug-Induced Nephropathy: Long-term use of certain medications, such as non-
steroidal anti-inflammatory drugs (NSAIDs), some antibiotics, and other nephrotoxic
drugs, can lead to kidney damage.
9. Autoimmune Diseases: Diseases such as systemic lupus erythematosus and Good-
pasture syndrome can cause the immune system to attack kidney tissues, leading to
glomerulonephritis and other renal conditions.
10. Chronic Obstruction: Conditions like tumors, strictures, or an enlarged prostate
that obstruct urine flow can lead to hydronephrosis (swelling of the kidneys) and
progressive kidney damage.
11. Nephrosis (Nephrotic Syndrome):Nephrosis is a kidney disorder characterized by
damage to the tiny blood vessels (glomeruli) that filter waste and excess water from
the blood. This damage leads to the leakage of large amounts of protein into the urine
(proteinuria), resulting in low protein levels in the blood (hypoalbuminemia), swelling
(edema), and increased cholesterol and triglycerides (hyperlipidemia).
Common causes of nephrosis include diabetes, certain infections, autoimmune
disorders, and medications. It can also be a result of primary glomerular disease
or secondary to systemic conditions affecting the kidneys.

Common Renal Disease :

The common renal disease include :
 Glomerulonephritis
 Nephrosis
 CKD - Chronic kidney disease
 Renal Calculi

Reference:
National Kidney Foundation. (2023). “Causes of Kidney Disease.” https://www.kidney.org.