Mean corpuscular volume (MCV) is the average size of the red blood cells expressed in femtoliters (fl).
The MCV is an index of the size of the RBCs. When the MCV is below normal, the RBCs will be smaller than normal and are described as microcytic. When the MCV is elevated, the RBCs will be larger than normal and are termed macrocytic.
Normal value of MCV is 80-96 fl,
Increased MCV indicates Macrocytic anaemia.
The MCH is usually elevated in macrocytic anemias associated with vitamin B12 and folate deficiency. Normal value of MCH is 27-33 pg
The serum/blood urea nitrogen (BUN) test is a measure of the amount of nitrogen in the blood that comes from urea. Urea is a substance secreted by the liver, and removed from the blood by the kidneys.
The most common cause of an elevated BUN, azotemia, is poor kidney function.
High BUN also occurs in chronic glomerulonephritis, pyelonephritis and other causes of chronic kidney disease; with acute kidney failure, decreased renal perfusion (prerenal azotemia) as in shock.
Elevated serum Creatinine also indicates poor kidney function,or it indicates towards kidney failure.Although in case it is very mild.
GFR--glomerular filtration rate is the best test to measure level of kidney function and determine stage of kidney disease.
A low GFR indicates that kidney is not functioning properly.It is unable to excrete the metabolites.
Hope this helps