Comprehensive Electrolyte Imbalance Reference Chart

Definition: Electrolytes are substances whose molecules dissociate, or split, into ions when placed in water. Ions are electrically charged particles. Cations are positively charged ions (Na⁺, K⁺, Ca²⁺, Mg²⁺). Anions are negatively charged ions (HCO₃⁻, Cl⁻, PO₄³⁻). Most proteins bear a negative charge and are thus anions.

Normal Reference Values

Electrolyte Reference Range Alternative Units
Sodium (Na⁺) 135-145 mEq/L 135-145 mmol/L
Potassium (K⁺) 3.5-5.0 mEq/L 3.5-5.0 mmol/L
Calcium (Ca²⁺) - Total 8.6-10.2 mg/dL 2.15-2.55 mmol/L
Calcium (Ca²⁺) - Ionized 4.6-5.3 mg/dL 1.16-1.32 mmol/L
Magnesium (Mg²⁺) 1.5-2.5 mEq/L 0.75-1.25 mmol/L
Phosphate (PO₄³⁻) 2.4-4.4 mg/dL 0.78-1.42 mmol/L
Bicarbonate (HCO₃⁻) 22-26 mEq/L 22-26 mmol/L
Chloride (Cl⁻) 96-106 mEq/L 96-106 mmol/L
SODIUM (Na⁺)
Normal Range: 135-145 mEq/L (135-145 mmol/L)
Hypernatremia (Na⁺ >145 mEq/L)
Causes
Excessive Sodium Intake:
  • IV fluids: hypertonic NaCl, excessive isotonic NaCl, IV sodium bicarbonate
  • Hypertonic tube feedings without water supplements
  • Near-drowning in salt water
Inadequate Water Intake:
  • Unconscious or cognitively impaired individuals
Excessive Water Loss:
  • Insensible water loss (high fever, heatstroke, prolonged hyperventilation)
  • Osmotic diuretic therapy
  • Diarrhea
Diseases:
  • Diabetes insipidus
  • Primary hyperaldosteronism
  • Cushing syndrome
  • Uncontrolled diabetes mellitus
Manifestations
With Decreased ECF Volume:
  • Restlessness, agitation, lethargy, seizures, coma
  • Intense thirst, dry swollen tongue, sticky mucous membranes
  • Postural hypotension, decreased CVP, weight loss, increased pulse
  • Weakness, muscle cramps
With Normal or Increased ECF Volume:
  • Restlessness, agitation, twitching, seizures, coma
  • Intense thirst, flushed skin
  • Weight gain, peripheral and pulmonary edema, increased BP, increased CVP
Hyponatremia (Na⁺ <135 mEq/L)
Causes
Excessive Sodium Loss:
  • GI losses: diarrhea, vomiting, fistulas, NG suction
  • Renal losses: diuretics, adrenal insufficiency, Na⁺ wasting renal disease
  • Skin losses: burns, wound drainage
Inadequate Sodium Intake:
  • Fasting diets
Excessive Water Gain:
  • Excessive hypotonic IV fluids
  • Primary polydipsia
Diseases:
  • SIADH
  • Heart failure
  • Primary hypoaldosteronism
  • Cirrhosis
Manifestations
With Decreased ECF Volume:
  • Irritability, apprehension, confusion, dizziness, personality changes, tremors, seizures, coma
  • Dry mucous membranes
  • Postural hypotension, decreased CVP, decreased jugular venous filling, increased pulse, thready pulse
  • Cold and clammy skin
With Normal or Increased ECF Volume:
  • Headache, apathy, confusion, muscle spasms, seizures, coma
  • Nausea, vomiting, diarrhea, abdominal cramps
  • Weight gain, increased BP, increased CVP
POTASSIUM (K⁺)
Normal Range: 3.5-5.0 mEq/L (3.5-5.0 mmol/L)
Hyperkalemia (K⁺ >5.0 mEq/L)
Causes
Excess Potassium Intake:
  • Excessive or rapid parenteral administration
  • Potassium-containing drugs (e.g., potassium penicillin)
  • Potassium-containing salt substitute
Shift of Potassium Out of Cells:
  • Acidosis
  • Tissue catabolism (e.g., fever, crush injury, sepsis, burns)
  • Intense exercise
  • Tumor lysis syndrome
Failure to Eliminate Potassium:
  • Renal disease
  • Adrenal insufficiency
  • Medications: Angiotensin II receptor blockers, ACE inhibitors, heparin, potassium-sparing diuretics, NSAIDs
Clinical Manifestations
  • Fatigue, irritability
  • Muscle weakness, cramps
  • Loss of muscle tone
  • Paresthesias, decreased reflexes
  • Abdominal cramping, diarrhea, vomiting
  • Confusion
  • Irregular pulse
  • Tetany
ECG Changes
  • Tall, peaked T wave
  • Prolonged PR interval
  • ST segment depression
  • Widening QRS
  • Loss of P wave
  • Ventricular fibrillation
  • Ventricular standstill
Hypokalemia (K⁺ <3.5 mEq/L)
Causes
Potassium Loss:
  • GI losses: diarrhea, vomiting, fistulas, NG suction, ileostomy drainage
  • Renal losses: diuretics, hyperaldosteronism, magnesium depletion
  • Skin losses: diaphoresis
  • Dialysis
Shift of Potassium Into Cells:
  • Increased insulin release (e.g., IV dextrose load)
  • Insulin therapy (e.g., with diabetic ketoacidosis)
  • Alkalosis
  • Increased epinephrine (e.g., stress)
Lack of Potassium Intake:
  • Starvation
  • Diet low in potassium
  • Failure to include potassium in parenteral fluids if NPO
Clinical Manifestations
  • Fatigue
  • Muscle weakness, leg cramps
  • Soft, flabby muscles
  • Paresthesias, decreased reflexes
  • Constipation, nausea, paralytic ileus
  • Shallow respirations
  • Weak, irregular pulse
  • Hyperglycemia
ECG Changes
  • Flattened T wave
  • Presence of U wave
  • ST segment depression
  • Prolonged QRS
  • Peaked P wave
  • Ventricular dysrhythmias
  • First- and second-degree heart block
CALCIUM (Ca²⁺)
Normal Range: Total: 8.6-10.2 mg/dL (2.15-2.55 mmol/L) | Ionized: 4.6-5.3 mg/dL (1.16-1.32 mmol/L)
Hypercalcemia (Ca²⁺ >10.2 mg/dL)
Causes
Increased Total Calcium:
  • Hyperparathyroidism
  • Hematologic malignancy
  • Malignancies with bone metastasis
  • Prolonged immobilization
  • Vitamin A or D overdose
  • Paget's disease
  • Adrenal insufficiency
  • Thyrotoxicosis
  • Thiazide diuretics
  • Milk-alkali syndrome
  • Calcium-containing antacids
  • Mycobacterium infection
Increased Ionized Calcium:
  • Acidosis
Manifestations
  • Lethargy, weakness, fatigue
  • Decreased memory
  • Depressed reflexes
  • Increased BP
  • Confusion, psychosis
  • Anorexia, nausea, vomiting
  • Bone pain, fractures
  • Polyuria, dehydration
  • Nephrolithiasis
  • Seizures, coma
ECG Changes
  • Shortened ST segment
  • Shortened QT interval
  • Ventricular dysrhythmias
  • Increased digitalis effect
Hypocalcemia (Ca²⁺ <8.6 mg/dL)
Causes
Decreased Total Calcium:
  • Primary hypoparathyroidism
  • Renal insufficiency
  • Acute pancreatitis
  • Elevated phosphorus
  • Vitamin D deficiency, malnutrition
  • Magnesium deficiency
  • Bisphosphonates
  • Tumor lysis syndrome
  • Loop diuretics
  • Chronic alcoholism
  • Diarrhea
  • Decreased serum albumin
Decreased Ionized Calcium:
  • Alkalosis
  • Excess administration of citrated blood
Manifestations
  • Weakness, fatigue
  • Depression, irritability, confusion
  • Hyperreflexia, muscle cramps
  • Decreased BP
  • Numbness and tingling in extremities and region around mouth
  • Chvostek's sign
  • Trousseau's sign
  • Laryngeal and bronchial spasms
  • Tetany, seizures
ECG Changes
  • Elongation of ST segment
  • Prolonged QT interval
  • Ventricular tachycardia
MAGNESIUM (Mg²⁺)
Normal Range: 1.5-2.5 mEq/L (0.75-1.25 mmol/L)
Hypermagnesemia (Mg²⁺ >2.5 mEq/L)
Causes
  • Renal failure
  • IV administration of magnesium, especially for treatment of eclampsia
  • Tumor lysis syndrome
  • Hypothyroidism
  • Metastatic bone disease
  • Adrenal insufficiency
  • Antacids, laxatives
Manifestations
  • Lethargy, drowsiness
  • Muscle weakness
  • Urinary retention
  • Nausea, vomiting
  • Diminished deep tendon reflexes
  • Flushed, warm skin, especially facial
  • Decreased pulse, decreased BP
Hypomagnesemia (Mg²⁺ <1.5 mEq/L)
Causes
  • GI tract fluid losses (e.g., diarrhea, NG suction)
  • Chronic alcoholism
  • Malabsorption syndromes
  • Prolonged malnutrition
  • Increased urine output
  • Hyperglycemia
  • Proton pump inhibitor therapy
Manifestations
  • Confusion
  • Muscle cramps
  • Tremors, seizures
  • Vertigo
  • Hyperactive deep tendon reflexes
  • Chvostek's and Trousseau's signs
  • Increased pulse, increased BP, dysrhythmias
PHOSPHATE (PO₄³⁻)
Normal Range: 2.4-4.4 mg/dL (0.78-1.42 mmol/L)
Hyperphosphatemia (PO₄³⁻ >4.4 mg/dL)
Causes
  • Renal failure
  • Phosphate enemas (e.g., Fleet Enema)
  • Excessive ingestion (e.g., phosphate-containing laxatives)
  • Rhabdomyolysis
  • Tumor lysis syndrome
  • Thyrotoxicosis
  • Hypoparathyroidism
  • Sickle cell anemia, hemolytic anemia
  • Hyperthermia
Manifestations
  • Hypocalcemia
  • Numbness and tingling in extremities and region around mouth
  • Hyperreflexia, muscle cramps
  • Tetany, seizures
  • Calcium-phosphate precipitates in skin, soft tissue, cornea, viscera, blood vessels
Hypophosphatemia (PO₄³⁻ <2.4 mg/dL)
Causes
  • Malabsorption syndromes
  • Chronic diarrhea
  • Malnutrition, vitamin D deficiency
  • Parenteral nutrition
  • Chronic alcoholism
  • Phosphate-binding antacids
  • Diabetic ketoacidosis
  • Hyperparathyroidism
  • Refeeding syndrome
  • Respiratory alkalosis
Manifestations
  • CNS depression (confusion, coma)
  • Muscle weakness, including respiratory muscle weakness
  • Polyneuropathy, seizures
  • Cardiac problems (dysrhythmias, heart failure)
  • Osteomalacia, rickets
  • Rhabdomyolysis
CHLORIDE (Cl⁻)
Normal Range: 96-106 mEq/L (96-106 mmol/L)
Hyperchloremia (Cl⁻ >105-107 mEq/L)
Causes
Loss of Electrolyte-Free Fluid:
  • Dehydration (sweating, fever, inadequate water intake)
  • Diabetes insipidus
  • Hypermetabolic states
  • Skin burns
Loss of Hypotonic Fluid:
  • Diarrhea, vomiting
  • Osmotic diuretic therapy
Increased Sodium Chloride Intake:
  • Excessive IV saline administration
  • High sodium diet
  • Near-drowning in salt water
Other Causes:
  • Renal failure, kidney dysfunction
  • Trauma
  • Acid-base imbalances
  • Medications: corticosteroids, carbonic anhydrase inhibitors
  • Hyperchloremic metabolic acidosis
Manifestations
  • Often asymptomatic unless severe
  • Dyspnea, fatigue
  • Muscle weakness
  • Tachycardia
  • Hypertension, fluid retention
  • Edema, cardiovascular dysfunction
  • Signs of dehydration (dry mucous membranes)
  • Associated with hypernatremia symptoms
Treatment
  • Adequate hydration (2-3 quarts water daily)
  • Discontinue or modify causative medications
  • Treat underlying conditions
  • Severe cases: dialysis, sodium bicarbonate
  • Avoid excessive saline solutions
Hypochloremia (Cl⁻ <95-96 mEq/L)
Causes
GI Losses:
  • Prolonged vomiting or nasogastric suction
  • Diarrhea
  • Gastric fluid loss
  • Excessive use of laxatives
Renal Losses:
  • Diuretic therapy (loop and thiazide diuretics)
  • Bartter syndrome
  • Gitelman syndrome
  • Osmotic diuresis
Other Causes:
  • Chronic respiratory acidosis
  • Metabolic alkalosis
  • SIADH
  • Addison's disease
  • Cystic fibrosis
  • Low dietary chloride intake
  • Medications: corticosteroids, bicarbonates
  • Chemotherapy (electrolyte imbalances)
Manifestations
  • Often asymptomatic in mild cases
  • Muscle weakness, fatigue, lethargy
  • Muscle cramps, twitching
  • Apathy, confusion
  • Tetany-like symptoms (with hyponatremia)
  • Diaphoresis, fever
  • Neuromuscular irritability
  • Seizures (in severe cases)
  • Associated with metabolic alkalosis
  • Hypoventilation (compensatory)
Treatment
  • Treat underlying cause
  • Mild cases: increase dietary salt intake
  • Severe cases: IV sodium chloride solution
  • Modify or discontinue causative medications
  • Maintain adequate hydration
  • Monitor electrolyte levels regularly
  • Avoid caffeine and alcohol
Disclaimer: This chart is provided for educational purposes only and is not intended to replace clinical judgment, individualized diagnostic evaluation, or laboratory interpretation by licensed healthcare professionals. Electrolyte management decisions must account for patient-specific variables, comorbidities, and treatment context. PsychConcierge PLLC ("PsychConcierge.com") does not guarantee the completeness or applicability of this information to any particular clinical situation and disclaims all liability for outcomes associated with reliance on this content.