My furnace worked well for about 6 years. At that point I noticed an awful, propane-like smell (I'm on natural gas) from the exhaust outside my home. During my annual maintenance, the technician noted the heat exchangers were going bad.
Blood urea nitrogen (BUN) measures the amount of urea nitrogen in bloodstream. Urea is formed in liver as the end product of protein metabolism and digestion. Urea is transported to the kidneys for excretion. A normal range for blood urea nitrogen is generally 8 to 24 mg/dl for adult males and 6 to 21 mg/dl for females.Generally, a high blood urea nitrogen level means that the kidneys are not performing well, particularly if the result is above 50mg/dl.n adult men, normal range of serum creatinine is 0.9-1.3mg/dl; while in adult women, normal range of creatinine is 0.6 to 1.1mg/dl. A muscular young man will have a higher normal creatinine result than the senior people with poorer health conditions.
The creatinine levels in both urine and blood are determined and compared. Normal creatinine clearance for healthy women is 88-128 mL/min. and 97 to 137 mL/min. in males (normal levels may vary slightly between labs).Blood urea nitrogen (BUN) level is another indicator of kidney function.Urea is also a metabolic byproduct which can build up if kidney function is impaired.levated creatinine level signifies impaired kidney function or kidney disease. As the kidneys become impaired for any reason, the creatinine level in the blood will rise due to poor clearance of creatinine by the kidneys. Abnormally high levels of creatinine thus warn of possible malfunction or failure of the kidneys.