title: List of reference ranges for cerebrospinal fluid
text: # List of reference ranges for cerebrospinal fluid
  
  Following is a list of reference ranges for cerebrospinal fluid:
  
  ## Ions and metals
  
  Reference ranges for ions and metals in CSF :
  
  | Substance | Lower limit | Upper limit | Unit | Corresponds to % of that in plasma |
  | - | - | - | - | - |
  | Osmolality | 280 | 300 | mmol/L |
  | Sodium | 135 | 150 | mmol/L |
  | Potassium | 2.6 | 3.0 | mmol/L |
  | Chloride | 115 | 130 | mmol/L | >100% |
  | Calcium | 1.00 | 1.40 | mmol/L | ~50% |
  | Magnesium | 1.2 | 1.5 | mmol/L | >100% |
  | Iron | 0.2 | 0.4 | µmol/L |
  
  ## Other molecules
  
  Reference ranges for other molecules in CSF :
  
  | Substance | Lower limit | Upper limit | Unit | Corresponds to % of that in plasma |
  | - | - | - | - | - |
  | Glucose | 50 | 80 | mg/dL | ~60% |
  | Glucose | 2.2, 2.8 | 3.9, 4.4 | mmol/L | ~60% |
  | Protein | 15 | 40, 45 | mg/dL | ~1% |
  | Albumin | 7.8 | 40 | mg/dL | 0 - 0.7% - corresponding to an albumin (CSF/serum) quotient of 0 to $7x10^{−3}$ |
  | Lactate | 1.1 | 2.4 | mmol/L |
  | Creatinine | 50 | 110 | µmol/L |
  | Phosphorus | 0.4 | 0.6 | µmol/L |
  | Urea | 3.0 | 6.5 | mmol/L |
  | Carbon dioxide | 20 | 25 | mmol/L |
  
  ## Other CSF constituents
  
  Reference ranges for other CSF constituents :
  
  | Substance | Lower limit | Upper limit | Unit |
  | - | - | - | - |
  | RBCs | n/a | 0 / negative | cells/µL or $cells/mm^3$ |
  | WBCs | 0 | 3 | cells/µL $cells/mm^3$ |
  | pH | 7.28 | 7.32 | (-log M) |
  | $PCO_2$ | 44 | 50 | mmHg |
  | $PCO_2$ | 5.9 | 6.7 | kPa |
  | $PO_2$ | 40 | 44 | mmHg |
  | $PO_2$ | 5.3 | 5.9 | kPa |
  