Normal Creatinine Levels By Age

Normal Creatinine Levels By Age

What is Creatinine?

Creatinine is the most reliable parameter to assess the functioning of your kidneys. Creatinine is released after the breakdown of creatinine phosphate present in the muscles. It is therefore a chemical waste substance released due to muscular metabolism. Normal creatinine levels tend to vary with age.

Creatine, the precursor for creatinine is synthesized in the liver. About 2% of creatine is converted into creatinine daily. In a normal, healthy individual, creatinine is excreted from the kidneys. Extra-renal excretion of creatinine occurs only when there is severe impairment of renal function.

Serum creatinine is an index to monitor renal function while being exposed to nephrotoxic drugs, for acute kidney injury or chronic renal failure or in conditions of shock or dehydration where the renal function seems to be impaired.

How is Creatinine Measured?

Serum creatinine is often measured along with a test for blood urea levels. Creatinine can be measured from serum, plasma or urine. Another blood test called Creatinine Clearance is used to estimate the glomerular filtration rate.

Levels of serum creatinine have an inverse relation with Glomerular Filtration Rate (GFR). Yet, values of creatinine can be influenced by temperature, certain substances and drugs. This means that creatinine, although the most reliable marker of kidney function is often not the most accurate test.

Certain Substances may Interfere with Measurement of Creatinine Levels

  1. Proteins
  2. Ketones
  3. Glucose
  4. Bilirubin
  5. Fatty acid
  6. Urea and urate
  7. Ascorbate

Some Drugs which Interfere with Measurement of Creatinine Levels are:

  1. Cephalosporins
  2. Methanol
  3. Metabolites
  4. Calcitrol
  5. NSAIDs
  6. Chemotherapy drugs

Normal Serum Creatinine Levels by Age & Gender:

Creatinine levels are the lowest during the neonatal period. Serum creatinine levels are higher in men than in women.

Creatinine is a waste product excreted through urine in normal healthy individuals. Therefore its levels can be measured by both blood and urine.

Age group Normal range in Males (mg/dL) Normal range in Females (mg/dL)
1 – 3 months 0.2 – 0.75 0.3 – 0.6
3 – 6 months 0.3 – 0.7 0.3 – 0.6
6 – 12 months 0.2 – 0.7 0.2 – 0.75
1 – 3 years 0.2 – 0.8 0.2 – 0.8
4 – 10 years 0.3 – 0.8 0.35 – 0.75
11 – 15 years 0.5 – 1.0 0.5 – 0.95
16 – 20 years 0.6 – 1.2 0.6 – 1.0
21 – 30 years 0.2 – 1.2 0.3 – 1.2
31 – 40 years 0.6 – 1.6 0.3 – 1.0
41 – 50 years 0.7 – 1.4 0.4 – 0.9
51 – 60 years 0.7 – 1.3 0.6 – 1.3

No special preparation is required for measuring serum creatinine levels. Blood is drawn and sent for analysis at your clinician’s office.

Normal Urine Creatinine Levels By Age:

Age group Normal range (mg/dL)
1 – 6 months 2 – 32
7 – 11 months 2 – 36
1 – 2 years 2 – 128
3 – 8 years 2 – 149
9 – 12 years 1 – 183
>12 years Male 20 – 370
>12 years Female 20 – 320

To test creatinine levels in urine, urine needs to be collected over a period of 24 hours and the container has to be given at the laboratory for analysis.

There are no risks involved in testing for creatinine levels in blood or urine. Both blood and urine creatinine levels in elderly people tend to be high as a part of the normal aging process and also due to certain co-morbidities which may develop with an advancing age.

When are Creatinine Levels Low?

Creatinine levels can be low in the following conditions:

  • Low Muscle Mass – Due to dietary deficiency of protein, meat-free diet and malnutrition, aging, muscular disorders, chronic glucocorticoid therapy and amputations.
  • Liver Diseases – Reduce creatine production.
  • Pregnancy – GFR and kidney size increases during pregnancy especially in 3rd trimester.
  • Raised anti-diuretic hormone

When are Creatinine Levels High?

Creatinine Levels are High in the Following Conditions:

  • Kidney Pathologies – Acute and chronic renal failure, diffuse and nodular glomerulosclerosis.
  • Trauma, crush injuries or febrile states
  • Congestive heart failure
  • Diabetes – in both types I and II diabetes.
  • Reduced tubular secretion
  • Large Muscle Mass – From high meat diet, anabolic steroids and weight lifters.
  • Acute Rhabdomylosis – Condition in which a severe muscular injury or skeletal muscular breakdown occurs which results in the release of myoglobin into the bloodstream.

Symptoms of High Creatinine Levels:

Nausea, vomiting, fatigue, chest pain, muscular cramps, poor urine output, swelling of hands and legs and high blood pressure.

Both high and low creatinine levels can be alarming because any kind of change indicates a serious impairment of health status. Slight harmless variations can occur due to factors mentioned above.

How To Reduce Creatinine Level to Normal Range?

Getting creatinine levels to the normal range requires the use of medications as well a healthy diet and lifestyle modifications. Treating the underlying cause is of prime importance. Certain home remedies can also help in lowering or regularizing creatinine levels.

  1. Plenty of Water: Since kidneys are responsible for excreting creatinine, drinking ample water aids the renal function. Water intake must be monitored in patients with chronic renal failure.
  2. Avoid Heavy Exercise: Creatinine is a by product of creatine phosphate found in muscles. Any form of vigorous exercise increase conversion of creatine to creatinine. Opt for milder forms of exercises like walking or yoga.
  3. Avoid Creatine Containing Supplements: Some athletes or gym freaks habitually take supplements which contain creatine to gain muscle mass.
  4. Limit Protein Intake – High protein diet or meat and eggs contain proteins which raise creatinine levels. Vegetarian sources include peas, soya beans, legumes and pulses.
  5. Increase Intake of Fiber: Food substances rich in fiber like fruits, vegetables, whole grains and also fiber supplements help in reducing creatinine levels.
  6. Chitosan: A study was conducted which showed that chitosan could significantly reduce creatinine levels. Professional advice must be sought before using this substance.
  7. Saliva: A clinical study conducted recently suggested saliva as the most efficient substance in the treatment of high levels of creatinine. Saliva has been used in the ancient Chinese medicine for the same.
  8. Chamomile Tea: Chamomile has beneficial effects in a wide number of both physical and mental illnesses. Chamomile is known to reduce creatinine levels.
  9. Stinging Nettle and Dandelion Root – These are ancient ayurvedic and natural herbs which are known for their effects of flushing out metabolic wastes from the body and increasing urinary output.
  10. Cinnamon: This kitchen spice is known for stimulating kidney function and also to regulate blood sugar levels in diabetics. The best part is cinnamon can be added to any meal or tea, coffee or even infused with water.
  11. Corn Silk Tea: This herb has a powerful diuretic effect upon kidneys. It reduces creatinine as well as edema
Medically Reviewed By
Dr. Kaushal M. Bhavsar (MBBS, MD)Assistant Professor in Pulmonary Medicine, GMERS Medical College, Ahmedabad