Know Your Numbers


A branch of the Six Counties Kidney Patients Association - Registered Charity No. 282361

As a kidney patient you will get used to giving blood!

This page gives information (taken from Renal PatientView) about some of the things your blood is being tested for and also the results which are considered 'normal'. This information is particularly for haemodialysis patients.

If you have any queries about your blood results you should speak to your nurses or doctor.

Creatinine	This is the best routine blood test for measuring how well kidneys are working. It is produced by muscles and put out by the kidneys. Creatnine levels do not rise much in early kidney disease - they may be normal until more than 50% of kidney function is lost in some patients.	less than 60	Suggests a very small person, or someone with little muscle (including small children).
		60-120	'Normal' - but there could still be reduced kidney function
		120-200	Mild to moderate kidney failure - but in someone with little muscle, 200 could sometimes mean more severe kidney failure.
		300+	Moderate to severe kidney failure. Most dialysis patients have creatinine measurements over 300 all of the time.
Urea	Urea is a small molecule produced from protein and put out by the kidneys, so levels rise in kidney failure. It is affected by: How much protein you eat (it is low if you do not eat) Whether you have taken in enough fluid (it rises if you are dehydrated)	below 3.5	Low. Possibly low protein intake from diet. A low urea is normal in pregnancy.
		3.6-5.0	Normal
		5.0+	High. Suggests renal failure, dehydration, high protein intake, or bleeding. Levels over 8-10 are unlikely to be due to diet alone.
		25+	Very high - suggests serious illness or renal failure
Haemoglobin [Hb]	Haemoglobin is the red stuff in blood. It carries oxygen around the body. Normal is slightly higher in men than women. Note that many labs report Hb as g/dl instead of g/litre. This gives results exactly one tenth of those shown here.	below 80	Likely to make you feel breathless and tired. Many causes including bleeding, but it can occur with just renal failure.
		100-120	Commonly the target for Hb in patients treated with EPO (see below). Still slightly anaemic for some people.
		130-180 (men) 115-165 (women)	Normal
		180+	This is unusual in kidney disease, except sometimes after kidney transplantation.
Potassium [K]	Potassium comes from diet - especially fruit, vegetables, nuts. Levels in blood are often high in people with kidney diseases. Too high can lead to heart attack.	below 3.5	Too low. Common after haemodialysis, when it is usually temporary. If below 3.0, may feel weak.
		3.5-5.0	Normal
		5.0-6.0	High but usually not dangerous - getting closer to dangerous at 6.0. It is common to arrive for haemodialysis with a slightly high potassium level.
		6.5+	Dangerously high
Calcium [Ca]	Low calcium is usual in people with untreated kidney disease, mostly because the healthy kidney is involved in processing of Vitamin D.	less than 2.1	Low calcium causes an increase in PTH, which then moves calcium out of bones and thins them. 'Low' calcium may be normal in patients with a low serum albumin.
		2.1-2.6	Normal in patients with a normal serum albumin
		2.6+	Too high - risk of calcification of arteries and itching.
		3.0+	Likely to make you very unwell.
Phosphate [PO4]	Phosphate levels are high in kidney failure, and this may cause itching and calcium deposits in the body, especially in arteries. Patients are often asked to limit the amount of phosphate in their diet, and to take tablets that stop the phosphate that you eat from getting into you - 'phosphate binders'. These must be taken with food to work.	less than 0.8	Very low levels cause severe weakness and bone problems.
		0.8-1.4	Normal
		1.5-1.8	Acceptable in dialysis patients and patients with severe renal failure.
		2.0+	Too high - risk of bone disease, and of calcium deposits forming in arteries and elsewhere.
White blood cells [wbc]	White blood cells fight infection in the body. Their level is often raised in the presence of infection, but they may become low with some infections, as well as with some drugs.	below 4	Very low counts (especially neutrophil counts; or total counts below 2 or 3) indicate serious risk of infection, or sign of severe infection. Can be caused by drugs or blood diseases.
		4-11	Normal
		over 11	Often suggests infection though there are other causes, including treatment with high doses of steroids. Rarely, very high counts may occur in blood diseases.

This is only an example of some measurements which are made. You may have different tests, for instance if you are diabetic.

Prior to starting dialysis you will probably be prescribed with many pills (some people are on more than 15 a day!) to control some of these figures. Once on haemodialysis some of these medicines may no longer be required.

Always be sure to take your medicines as advised by your doctor.
Report any side-effects as there may be an alternative prescription available.
Never stop taking medication without first talking to your doctor.

If in any doubt about drugs or blood tests speak to the nursing staff.