Hypernatremia: Greater than 145
Signs and symptoms of hypernatremia: mental status changes, confusion, agitation, ataxia, convulsion, hypertension, tachycardia, decreased urine output, thirst, pulmonary edema, dyspnea, respiratory arrest

Hyponatremia: Less than 135
Signs and symptoms of hyponatremia: Nausea, vomiting, abdominal cramps, muscle twitching, confusion, tachycardia, seizures, or coma

Normal: 135 – 145
Be aware of fluid restrictions. Fluid is directly related to sodium. The higher sodium, the higher the fluid retention.


Useful for acid/base imbalance renal function, neuromuscular function, cardiac muscle contraction, and conductivity.
Hyperkalemia: Greater than 5
Exercise can worsen the heart.

Hypokalemia: Less than 3.5
Oral potassium may be administered. Oral potassium is fast acting.

Critical levels: Less than 2.5 or greater than 6.6
Normal range: 3.5 to 5


Facilitates exchange of oxygen and carbon dioxide in the red blood cells.

Hyperchloremia: Greater than 108
Weakness, lethargy, and dyspnea.

Hypochloremia: Less than 96
Muscle weakness, twitching, and shallow breathing.

Critical values: Less than 80 or greater than 115
Normal range: 96-108


Measures level of carbon dioxide in blood.
Normal: 22 – 28

Elevated levels of CO2: Respiratory acidosis or metabolic alkalosis

Decreased levels of CO2: Respiratory alkalosis or Metabolic acidosis


Measures kidney and liver function.
Critical value: Greater than 100
Normal: 10 – 20 mg/dL

Elevated BUN levels may show signs and symptoms of altered mental status and convulsions.


Measures kidney function.
Normal: M: 0.6 – 1.2 mg/dL
Normal: F: 0.5 – 1.1 mg/dL

Elevated creatinine signs and symptoms are fatigue, dyspnea, confusion, and dehydration.


Normal: You’ll hear 70-110 or 60-120. Neither is wrong.
Hypoglycemia: Less than 60
Signs and symptoms of hypoglycemia include headache, weakness, shakiness, clammy feeling, impaired muscle control, and blurred vision. Patients are given a quick carbonhydrate snack.

Hyperglycemia: Greater than 250
Prediabetes: Greater than 120
Diabetes: Greater than 130
Critical value: Less than 60 or greater than 300