Renal Function Tests (RFTs)
Definitions: Renal Function Tests (RFTs) are a group of tests used to assess how well the kidneys are
functioning. These tests help in diagnosing kidney diseases, monitoring the progression of kidney
conditions, and evaluating the effectiveness of treatments.
Panel Test Names, Their Functions, and Normal Ranges:
1. Serum Creatinine:
o Definition: Measures the level of creatinine in the blood. Creatinine is a waste product
from muscle metabolism that the kidneys filter out.
o Normal Range: 0.6-1.2 mg/dL for men and 0.5-1.1 mg/dL for women.
o Significance: High levels indicate impaired kidney function as the kidneys are not
effectively filtering creatinine from the blood.
2. Blood Urea Nitrogen (BUN):
o Definition: Measures the amount of urea nitrogen in the blood. Urea is a waste product
from protein metabolism.
o Normal Range: 7-20 mg/dL.
o Significance: High BUN levels can suggest kidney dysfunction or dehydration, while
low levels might indicate liver disease or malnutrition.
3. Estimated Glomerular Filtration Rate (eGFR):
o Definition: An estimate of how much blood the kidneys filter per minute. It's calculated
based on serum creatinine levels, age, sex, and body size.
o Normal Range: 90-120 mL/min/1.73 m².
o Significance: Lower eGFR values indicate reduced kidney function. eGFR is a key
indicator of chronic kidney disease (CKD).
4. Urinalysis:
o Definition: A test of the urine that checks for the presence of proteins, glucose, blood,
and other substances.
o Normal Findings: Negative for protein, glucose, and blood; clear color; pH of 4.5-8.0.
o Significance: Helps detect kidney disease, urinary tract infections (UTIs), and other
conditions. Abnormal findings can indicate kidney damage or infection.
5. Serum Electrolytes:
o Definition: Measures levels of key electrolytes such as sodium, potassium, and chloride
in the blood.
o Normal Ranges:
Sodium: 135-145 mEq/L.
Potassium: 3.5-5.0 mEq/L.
Chloride: 98-107 mEq/L.
, o Significance: Abnormal levels can indicate kidney disease, as the kidneys regulate
electrolyte balance. Imbalances can affect heart and muscle function.
6. Cystatin C:
o Definition: Another marker used to estimate GFR. It is considered more reliable than
serum creatinine in some cases, especially in individuals with certain conditions like
muscle wasting.
o Normal Range: 0.6-1.2 mg/L.
o Significance: Elevated levels indicate impaired kidney function and can be a more
accurate marker than creatinine in certain populations.
General Significance:
Diagnosing Kidney Conditions: RFTs are crucial for identifying conditions such as acute kidney
injury, chronic kidney disease, and other disorders affecting kidney function.
Monitoring Disease Progression: They help track the progression of kidney disease and
evaluate the response to treatment.
Assessing Treatment Effectiveness: RFTs can indicate how well a treatment is working and
whether any adjustments are needed.
Detecting Early Problems: Regular RFTs can help detect kidney issues early before symptoms
become apparent, allowing for timely intervention.
Overall Health Check: These tests can also provide information about other health conditions
that affect kidney function, such as diabetes and hypertension.
RFTs play a vital role in maintaining kidney health by providing valuable insights into kidney function
and aiding in the early detection and management of kidney-related conditions. The kidneys are essential
for filtering waste products from the blood, balancing body fluids, and regulating blood pressure, making
these tests crucial for overall health management.
Liver Function Tests (LFTs)
Definitions: Liver Function Tests (LFTs) are a group of blood tests that provide information about the
state of a person's liver. They help diagnose liver diseases, monitor the progression of existing liver
conditions, and evaluate the effectiveness of treatment.
Panel Test Names, Their Functions, and Normal Ranges:
1. Alanine Aminotransferase (ALT):
o Definition: An enzyme found predominantly in the liver that plays a critical role in
converting proteins into energy for the liver cells.
o Normal Range: 7-56 units per liter (U/L).
o Significance: High levels often indicate liver damage or inflammation, such as hepatitis, liver
cirrhosis, or damage from medications or toxins. ALT is a more specific marker of liver
injury compared to AST.
2. Aspartate Aminotransferase (AST):
Definitions: Renal Function Tests (RFTs) are a group of tests used to assess how well the kidneys are
functioning. These tests help in diagnosing kidney diseases, monitoring the progression of kidney
conditions, and evaluating the effectiveness of treatments.
Panel Test Names, Their Functions, and Normal Ranges:
1. Serum Creatinine:
o Definition: Measures the level of creatinine in the blood. Creatinine is a waste product
from muscle metabolism that the kidneys filter out.
o Normal Range: 0.6-1.2 mg/dL for men and 0.5-1.1 mg/dL for women.
o Significance: High levels indicate impaired kidney function as the kidneys are not
effectively filtering creatinine from the blood.
2. Blood Urea Nitrogen (BUN):
o Definition: Measures the amount of urea nitrogen in the blood. Urea is a waste product
from protein metabolism.
o Normal Range: 7-20 mg/dL.
o Significance: High BUN levels can suggest kidney dysfunction or dehydration, while
low levels might indicate liver disease or malnutrition.
3. Estimated Glomerular Filtration Rate (eGFR):
o Definition: An estimate of how much blood the kidneys filter per minute. It's calculated
based on serum creatinine levels, age, sex, and body size.
o Normal Range: 90-120 mL/min/1.73 m².
o Significance: Lower eGFR values indicate reduced kidney function. eGFR is a key
indicator of chronic kidney disease (CKD).
4. Urinalysis:
o Definition: A test of the urine that checks for the presence of proteins, glucose, blood,
and other substances.
o Normal Findings: Negative for protein, glucose, and blood; clear color; pH of 4.5-8.0.
o Significance: Helps detect kidney disease, urinary tract infections (UTIs), and other
conditions. Abnormal findings can indicate kidney damage or infection.
5. Serum Electrolytes:
o Definition: Measures levels of key electrolytes such as sodium, potassium, and chloride
in the blood.
o Normal Ranges:
Sodium: 135-145 mEq/L.
Potassium: 3.5-5.0 mEq/L.
Chloride: 98-107 mEq/L.
, o Significance: Abnormal levels can indicate kidney disease, as the kidneys regulate
electrolyte balance. Imbalances can affect heart and muscle function.
6. Cystatin C:
o Definition: Another marker used to estimate GFR. It is considered more reliable than
serum creatinine in some cases, especially in individuals with certain conditions like
muscle wasting.
o Normal Range: 0.6-1.2 mg/L.
o Significance: Elevated levels indicate impaired kidney function and can be a more
accurate marker than creatinine in certain populations.
General Significance:
Diagnosing Kidney Conditions: RFTs are crucial for identifying conditions such as acute kidney
injury, chronic kidney disease, and other disorders affecting kidney function.
Monitoring Disease Progression: They help track the progression of kidney disease and
evaluate the response to treatment.
Assessing Treatment Effectiveness: RFTs can indicate how well a treatment is working and
whether any adjustments are needed.
Detecting Early Problems: Regular RFTs can help detect kidney issues early before symptoms
become apparent, allowing for timely intervention.
Overall Health Check: These tests can also provide information about other health conditions
that affect kidney function, such as diabetes and hypertension.
RFTs play a vital role in maintaining kidney health by providing valuable insights into kidney function
and aiding in the early detection and management of kidney-related conditions. The kidneys are essential
for filtering waste products from the blood, balancing body fluids, and regulating blood pressure, making
these tests crucial for overall health management.
Liver Function Tests (LFTs)
Definitions: Liver Function Tests (LFTs) are a group of blood tests that provide information about the
state of a person's liver. They help diagnose liver diseases, monitor the progression of existing liver
conditions, and evaluate the effectiveness of treatment.
Panel Test Names, Their Functions, and Normal Ranges:
1. Alanine Aminotransferase (ALT):
o Definition: An enzyme found predominantly in the liver that plays a critical role in
converting proteins into energy for the liver cells.
o Normal Range: 7-56 units per liter (U/L).
o Significance: High levels often indicate liver damage or inflammation, such as hepatitis, liver
cirrhosis, or damage from medications or toxins. ALT is a more specific marker of liver
injury compared to AST.
2. Aspartate Aminotransferase (AST):
