Normal Vital Values and Reference Ranges
Comprehensive reference of normal values for vital signs and laboratory findings relevant to physical therapy practice
Basic Vital Signs
| Parameter | Adult Reference Range | Pediatric Reference Range | Notes | Clinical Significance |
|---|---|---|---|---|
| Body Temperature | 36.5-37.5°C (97.7-99.5°F) |
Newborn: 36.5-37.5°C Infant/Child: 36.5-37.5°C Adolescent: Same as adult |
Varies by measurement method (oral, rectal, tympanic) | Elevation indicates fever; significant decrease indicates hypothermia |
| Heart Rate | 60-100 beats/min |
Newborn: 100-160 beats/min Infant: 90-150 beats/min Toddler: 80-140 beats/min School-age: 70-120 beats/min Adolescent: 60-100 beats/min |
Lower in athletes and during sleep; higher during exercise and stress | Tachycardia >100 bpm; bradycardia <60 bpm in adults |
| Blood Pressure |
Systolic: 90-120 mmHg Diastolic: 60-80 mmHg |
Newborn: 60-90/30-60 mmHg 1-12 months: 70-100/40-65 mmHg 1-5 years: 80-110/40-70 mmHg 6-12 years: 85-120/45-75 mmHg 13-18 years: 90-120/50-80 mmHg |
Varies with activity, stress, medications, and position | Hypertension >130/80 mmHg; hypotension <90/60 mmHg |
| Respiratory Rate | 12-20 breaths/min |
Newborn: 30-60 breaths/min Infant: 20-40 breaths/min Toddler: 20-30 breaths/min School-age: 15-25 breaths/min Adolescent: 12-20 breaths/min |
Measured at rest; increases with exercise and illness | Tachypnea >20 breaths/min; bradypnea <12 breaths/min in adults |
| Oxygen Saturation (SpO₂) | 95-100% | 95-100% (all ages) | Measured by pulse oximetry | <90% indicates significant hypoxemia requiring intervention |
Assessment Tips
- Blood Pressure: Ensure proper cuff size (cuff bladder encircles 80% of arm); patient should be seated with back supported, arm at heart level, feet on floor
- Heart Rate: Count for 60 seconds if irregular; assess quality and rhythm in addition to rate
- Respiratory Rate: Observe without patient's awareness to avoid conscious alteration of breathing pattern
- Temperature: Consistent method and site should be used for serial measurements
- Oxygen Saturation: Nail polish, cold extremities, and poor perfusion can affect accuracy
Clinical Considerations
- Always interpret vital signs in the context of the patient's clinical presentation
- Consider the patient's baseline values when available
- Trending of vital signs over time may be more important than absolute values
- Position changes can significantly affect readings, particularly blood pressure
- Age, activity level, medications, and time of day all influence vital signs
Hematologic Values
| Parameter | Adult Reference Range | Pediatric Reference Range | Notes | Clinical Significance |
|---|---|---|---|---|
| Hemoglobin |
Males: 13.5-17.5 g/dL Females: 12.0-15.5 g/dL |
Newborn: 14.0-24.0 g/dL 2 months: 9.0-14.0 g/dL 1 year: 10.0-14.0 g/dL Children: 11.5-15.5 g/dL |
Varies by altitude and smoking status | Decreased in anemia; increased in polycythemia, dehydration |
| Hematocrit |
Males: 41-50% Females: 36-46% |
Newborn: 43-75% 2 months: 28-42% 1 year: 29-41% Children: 33-45% |
Approximately 3x hemoglobin value | Decreased in anemia, hemorrhage; increased in polycythemia, dehydration |
| Red Blood Cells (RBC) |
Males: 4.5-5.9 x 10¹²/L Females: 4.0-5.2 x 10¹²/L |
Newborn: 4.8-7.1 x 10¹²/L 2 months: 3.1-4.5 x 10¹²/L Children: 3.9-5.3 x 10¹²/L |
Varies with age, sex, and altitude | Decreased in anemia; increased in polycythemia |
| White Blood Cells (WBC) | 4.5-11.0 x 10⁹/L |
Newborn: 9.0-30.0 x 10⁹/L 1 year: 6.0-17.5 x 10⁹/L Children: 5.0-14.5 x 10⁹/L |
Differential count also important | Increased in infection, inflammation; decreased in certain infections, bone marrow suppression |
| Platelets | 150-450 x 10⁹/L | 150-450 x 10⁹/L (all ages) | May be slightly lower in pregnancy | Decreased in thrombocytopenia; increased in reactive thrombocytosis |
Biochemical Values
| Parameter | Adult Reference Range | Pediatric Reference Range | Notes | Clinical Significance |
|---|---|---|---|---|
| Sodium | 135-145 mEq/L | 135-145 mEq/L (all ages) | Tightly regulated by kidneys | Hyponatremia <135 mEq/L; hypernatremia >145 mEq/L |
| Potassium | 3.5-5.0 mEq/L |
Newborn: 3.7-5.9 mEq/L Child/Adolescent: 3.4-4.7 mEq/L |
Most intracellular; small changes significant | Hypokalemia <3.5 mEq/L; hyperkalemia >5.0 mEq/L |
| Chloride | 96-106 mEq/L | 96-106 mEq/L (all ages) | Follows sodium changes | Altered in acid-base disorders |
| Bicarbonate | 22-29 mEq/L |
Newborn: 17-24 mEq/L Child/Adolescent: 20-28 mEq/L |
Reflects acid-base status | Decreased in metabolic acidosis; increased in metabolic alkalosis |
| Blood Urea Nitrogen (BUN) | 7-20 mg/dL |
Newborn: 4-18 mg/dL Child/Adolescent: 5-18 mg/dL |
Affected by protein intake and hydration | Elevated in renal dysfunction, dehydration, high protein diet |
| Creatinine |
Males: 0.7-1.3 mg/dL Females: 0.6-1.1 mg/dL |
Newborn: 0.3-1.0 mg/dL Infant: 0.2-0.5 mg/dL Child: 0.3-0.7 mg/dL Adolescent: 0.5-1.0 mg/dL |
Depends on muscle mass | Elevated in renal dysfunction |
| Glucose (fasting) | 70-99 mg/dL | 60-100 mg/dL (all ages) | Higher after meals | <70 mg/dL: hypoglycemia 100-125 mg/dL: prediabetes >126 mg/dL: diabetes mellitus |
| Calcium (total) | 8.5-10.5 mg/dL |
Newborn: 7.6-10.4 mg/dL Child/Adolescent: 8.8-10.8 mg/dL |
Affected by albumin levels | Hypocalcemia <8.5 mg/dL; hypercalcemia >10.5 mg/dL |
| Magnesium | 1.7-2.2 mg/dL | 1.7-2.3 mg/dL (all ages) | Often overlooked electrolyte | Hypomagnesemia <1.7 mg/dL; hypermagnesemia >2.2 mg/dL |
| Phosphorus | 2.5-4.5 mg/dL |
Newborn: 4.8-8.2 mg/dL Child: 4.5-5.5 mg/dL Adolescent: 2.9-5.4 mg/dL |
Higher in children due to bone growth | Inversely related to calcium |
Liver Function Tests
| Parameter | Adult Reference Range | Pediatric Reference Range | Notes | Clinical Significance |
|---|---|---|---|---|
| Albumin | 3.5-5.0 g/dL |
Newborn: 2.8-4.4 g/dL Child/Adolescent: 3.7-5.6 g/dL |
Major plasma protein | Decreased in liver disease, malnutrition, protein loss |
| Total Bilirubin | 0.1-1.2 mg/dL |
Newborn: <12 mg/dL 1 month+: <1.2 mg/dL |
Metabolite of hemoglobin | Elevated in liver disease, hemolysis, biliary obstruction |
| Alanine Transaminase (ALT) |
Males: 7-56 U/L Females: 7-45 U/L |
Newborn: 6-40 U/L Child/Adolescent: 5-45 U/L |
Primarily in liver cells | Elevated in liver damage, myocardial infarction |
| Aspartate Transaminase (AST) |
Males: 10-40 U/L Females: 9-32 U/L |
Newborn: 35-140 U/L Child/Adolescent: 15-55 U/L |
Found in liver, heart, muscle | Elevated in liver damage, myocardial infarction, muscle injury |
| Alkaline Phosphatase (ALP) | 40-130 U/L |
Newborn: 150-420 U/L Child: 100-320 U/L Adolescent: 100-390 U/L |
Higher during bone growth | Elevated in liver, bone, and biliary diseases |
Cardiac Markers
| Parameter | Reference Range | Notes | Clinical Significance |
|---|---|---|---|
| Troponin I | <0.04 ng/mL | Cardiac-specific protein | Elevated in myocardial injury |
| Troponin T | <0.01 ng/mL | Cardiac-specific protein | Elevated in myocardial injury |
| BNP (Brain Natriuretic Peptide) | <100 pg/mL | Age-dependent variation | Elevated in heart failure |
| CK-MB | <5% of total CK | Cardiac-specific isoenzyme | Elevated in myocardial injury |
Arterial Blood Gas Values
| Parameter | Reference Range | Notes | Clinical Significance |
|---|---|---|---|
| pH | 7.35-7.45 | Logarithmic scale | <7.35: acidemia; >7.45: alkalemia |
| PaO₂ | 80-100 mmHg | Decreases with age | <60 mmHg indicates respiratory failure |
| PaCO₂ | 35-45 mmHg | Reflects ventilation | >45 mmHg: hypercapnia; <35 mmHg: hypocapnia |
| HCO₃⁻ | 22-26 mEq/L | Metabolic component | Altered in metabolic acid-base disorders |
| Base Excess | ±2 mEq/L | Indicates metabolic status | Negative in metabolic acidosis; positive in metabolic alkalosis |
| O₂ Saturation | 95-100% | Calculated from PaO₂ | <90% indicates significant hypoxemia |
Pulmonary Function
| Parameter | Adult Reference Range | Notes | Clinical Significance |
|---|---|---|---|
| Forced Vital Capacity (FVC) | 80-120% of predicted | Varies by age, height, sex, ethnicity | Reduced in restrictive lung disease |
| Forced Expiratory Volume in 1 second (FEV₁) | 80-120% of predicted | Varies by age, height, sex, ethnicity | Reduced in obstructive and restrictive lung diseases |
| FEV₁/FVC Ratio | >0.70 (>70%) | Less affected by anthropometric factors | <0.70 indicates obstructive lung disease |
| Peak Expiratory Flow Rate (PEFR) | 400-600 L/min in adults | Varies by age, height, sex | Reduced in asthma and COPD |
| Total Lung Capacity (TLC) | 80-120% of predicted | Varies by age, height, sex, ethnicity | Reduced in restrictive lung disease; increased in obstructive lung disease |
Pulmonary Function Assessment Tips
- Proper technique is essential: Patient education and proper instruction are crucial for accurate results
- Multiple attempts: Best of three technically acceptable maneuvers should be recorded
- Contraindications: Recent surgery, unstable cardiovascular status, pneumothorax, active hemoptysis
- Interpretation factors: Consider patient's effort, cooperation, and understanding of instructions
- Bronchodilator reversibility: Increase in FEV₁ of >12% and >200 mL from baseline indicates significant bronchodilator response
Coagulation Studies
| Parameter | Reference Range | Notes | Clinical Significance |
|---|---|---|---|
| Prothrombin Time (PT) | 11-13.5 seconds | Varies by laboratory | Prolonged in liver disease, vitamin K deficiency, anticoagulant therapy |
| International Normalized Ratio (INR) | 0.8-1.2 | Standardized from PT | 2.0-3.0 target for warfarin therapy in most indications |
| Partial Thromboplastin Time (PTT) | 25-35 seconds | Varies by laboratory | Prolonged in hemophilia, heparin therapy, liver disease |
| Bleeding Time | 2-8 minutes | Not commonly used now | Prolonged in platelet disorders, von Willebrand disease |
| D-dimer | <500 ng/mL | Age-adjusted values may be used | Elevated in thrombosis, pulmonary embolism, DIC |
Clinical Considerations for Coagulation Tests
- PT/INR: Monitors extrinsic pathway and common pathway; used to monitor warfarin therapy
- PTT: Evaluates intrinsic pathway and common pathway; used to monitor heparin therapy
- D-dimer: High negative predictive value for venous thromboembolism
- Timing of collection: Critical for accurate results, especially when monitoring anticoagulant therapy
- Medications affecting results: Anticoagulants, antibiotics, NSAIDs can all affect coagulation tests