Category Archives: Serum Creatinine

I have acute kidney injury and I am on dialysis. What blood test can show my kidneys can work without dialysis?

The nephrologist who is prescribing your dialysis should be monitoring your serum creatinine, hemoglobin, potassium, bicarbonate level and your daily urine output. Decisions about stopping dialysis often involve reviewing all of this information and sometimes performing a 24 hour urine … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Dialysis, Diet/Nutrition, Kidney-Related Health Questions, Nephrologist, Serum Creatinine

I’m 38, 177 lb 5’11. Creatinine level last 3 years 1.31 average. The other day 1.38 and a eGFR of 58? I have always tested negative for protein in urine although do have bubbly/foamy urine, strong stream, no high blood pressure, and diabetes. Ultrasounds and CT all normal. Doctor just says may be normal for me but I’m concerned. Should I be pushing for more done?

In this circumstance, a carefully collected 24 hour urine collection for a creatinine clearance can reveal if your kidney function is actually normal. This may show that your creatinine generation rate is higher than average. This is usually associated with … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Kidney-Related Health Questions, Serum Creatinine

Have you ever heard of Gilberts Syndrome affecting serum creatinine levels in the body?

Gilbert’s syndrome is a genetic liver disease where the liver is unable to conjugate the bilirubin that is derived from red blood cells that are naturally degraded over time. It results in an elevation of the bilirubin in blood and … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Kidney-Related Health Questions, Serum Creatinine

Hey Doc, Thank you for answering my questions over last few months. One of my last questions in regards to filtration. If muscle mass can increase serum creatinine why do some bodybuilders or even stronger than average people have normal creatinine and others have elevated. I am nowhere near pro or even that big and I am elevated but other people are normal. Is it just everyone’s different and I have higher than normal creatinine production but other bodybuilders who are a lot bigger strong don’t. Or do their kidneys just work better. That is one thing that confuses me. My clearance says 136 I am filtering well but how can a bodybuilder twice my size have normal creatinine and normal/bigger than average like me don’t. Then say my function is normal? Thank you.

The serum creatinine is dependent on kidney function, muscle mass, any creatine supplement intake, steroid intake, other drug use, hydration and red meat intake. Each person’s creatinine is a function of each of these independently and the unique body physiology … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Kidney-Related Health Questions, Serum Creatinine

I have started having a scoop of collagen, type 1 and 3 in my tea about 5 times a week. When I had my last nephrologist visit, last week, my function, which has been at the 53-56 mark, had gone down to 46. The only change I have made in the last 6 months, is the addition of collagen powder to my diet. I have 1 kidney and donated the other 22 years ago. I currently take bp medicine and my bp has been great. The only diagnosis for my decreased kidney function, was that it was due to the high blood pressure. All tests for other culprits came back fine. Is the collagen safe for me? I never saw anything negative about it and kidney function, until today. I do not want to lose any more function than I already have. I am 55 years old and run about 22-26 miles a week. I also do step classes 2x a week and body pump 1x a week. This is all normal for me as I have been an avid exerciser my whole life. Is there a specific blood work test that can check my collagen levels? Any thoughts or facts about taking collagen powder would be appreciated. Thank you.

I do not know of any ill effects of collagen powder on kidney function. This is a natural substance for your body and likely is not having any effect on your kidney function. In the world of laboratory medicine, the … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, GFR, Hypertension/High Blood Pressure, Kidney-Related Health Questions, Nephrectomy / One kidney, Serum Creatinine

My GFR ranges from high 63 to low 34. Feb, 55; June, 34; July, 63; Aug, 44; Feb, bun 19, creatinine 1.0; June, 24; 1.5, July, 12, 0.9; Aug, 20, 1.2. No one is giving me an answer for this. Something is causing these fluctuations?

I cannot make any specific diagnosis based on the information that you present. I would suggest that you review this with a laboratory and possibly the director of the laboratory where this testing was done.  The serum creatinine is only … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Kidney-Related Health Questions, Serum Creatinine

Is feeling the inside temperature of the body a symptom of kidney disease? Is there any correlation between elevated creatinine and billrubin enzyme?

Patients with chronic kidney disease (CKD) commonly report feeling chilled or “cold” despite others feeling normal or “warm”. If someone has serious liver disease, the serum bilirubin may be elevated and the serum creatinine may be increased because of liver … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Chronic Kidney Disease, Kidney-Related Health Questions, Serum Creatinine

Good Morning Doc, Quick test question. Would the amount of water intake and urine volume in 24 hours affect the amount of creatinine filtered/secreted each day? Would high volume increase (U) creatinine or if the volume was half, would the urine just be more concentrated with the same amount of creatinine? (My highest serum creatinine ever was 1.7 but I cut back meat and worked out for this test.) For example, on my 24 hour creatinine clearance I urinated 3400ml (reference range was 600-1600; obviously due to high hydration). My urine creatinine was 81.6mg/dl and my creatinine/24hour urine was 2774mg/24r. My serum creatinine came to 1.41, which made my creatinine clearance 136.6ml/min.

The amount of volume in a 24 hour urine collection does not change the creatinine clearance. It may occasionally have an limited impact if someone was ill and dehydrated with one collection and then aggressively hydrated with another. This might … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Diet/Nutrition, Kidney-Related Health Questions, Serum Creatinine

Hey Doc, I have been seeing a therapist for health anxiety but I am still very anxious about my kidneys ever since my PCP scared me to death and I read about elevated serum creatinine/low eGFR meaning kidney disease. My nephrologist said I am okay and I am seeking a second opinion in three weeks. I am 23, used to work out everyday until the 1.7 reading, and ate pounds of protein a day. Including supplements but stopped at the 1.54 reading. My last serum creatinine was 1.41 and highest were 1.54 and 1.7. No protein or blood in urine, normal ultrasound and ct scan, and creatinine clearance of 136.6ml/min. All good signs to show normal function but I am still concerned and worried. My anxiety is so much better and I am not as worried but still very skeptical I may have CKD. I’ve thought about a Cystatin C test and maybe even spending $600 to do inulin clearance. Just looking for opinion and maybe advice/questions to ask/tests to request going into seeing the second opinion.

In your case, you need to allow your physician to interpret kidney function testing. There is a great deal of frustration associated with interpretation of kidney function testing. Your physician should rely on repetitive testing. Averaging repetitive testing is the … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Chronic Kidney Disease, GFR, Kidney-Related Health Questions, Serum Creatinine

Does the faucet analogy really apply to kidneys? If you increase protein intake and muscle mass does the blood fill with more creatinine? Should normal kidneys filter faster and more blood or can they only filter a certain amount per minute hence the increase in serum creatinine. Or does protein damage kidneys? I’ve seen counter-intuitive studies and the analogy doesn’t work.

I’m not sure I understand the faucet analogy. Kidney function is what ever kidney function is. Our frustration is the imperfection of our ways of estimating kidney function with the current technology. Our current scientific knowledge allows us several ways … Continue reading

Posted in Ask the Doctor, Blood/Urine Testing For Kidney Disease, Diet/Nutrition, GFR, Kidney-Related Health Questions, Serum Creatinine