Electrolytes Study Chart

Important exam reminders:

Hypo means LOW. Hyper means HIGH.
Potassium is especially important for heart rhythm.
Calcium is important for bones and muscle contraction.
Magnesium helps muscles relax.
Sodium controls fluid balance and affects the brain.
Phosphorus helps produce energy.
Chloride helps maintain acid-base balance.

Electrolyte	Hypo (Low)	Hyper (High)
Sodium	Confusion, headache, seizures	Thirst, dry mouth, confusion
Potassium	Weakness, constipation, irregular heartbeat	Weakness, tingling, cardiac arrest risk
Calcium	Tingling, spasms, tetany	Constipation, kidney stones, weakness
Magnesium	Tremors, increased reflexes, seizures	Decreased reflexes, low BP, slow breathing
Chloride	Cramps, weakness, shallow breathing	Thirst, dehydration, rapid breathing
Phosphorus	Weakness, fatigue, bone pain	Cramps, tingling, low-calcium symptoms

1. Sodium (Na⁺)

Normal: 135–145 mEq/L

Category	What to know
Importance	Fluid balance, blood volume, brain and nerve function.
Hypo: Low sodium	Headache, confusion, nausea, muscle cramps, seizures.
Hyper: High sodium	Extreme thirst, dry mouth, restlessness, confusion, seizures.
Nursing interventions	Monitor sodium and neurological status. Low sodium may require fluid restriction or prescribed sodium replacement. High sodium may require gradual fluid replacement.
Foods to eat	Low: Broth, salted crackers, cheese, depending on treatment. High: Fresh fruits, vegetables, and low-sodium foods.

2. Potassium (K⁺)

Normal: 3.5–5.0 mEq/L

Category	What to know
Importance	Heart rhythm, muscle contractions, nerve function.
Hypo: Low potassium	Muscle weakness, fatigue, cramps, constipation, irregular heartbeat.
Hyper: High potassium	Muscle weakness, tingling, nausea, dangerous heart rhythm changes, possible cardiac arrest.
Nursing interventions	Monitor potassium and ECG. Low potassium may require potassium replacement. High potassium may require prescribed medications to lower potassium. Never give potassium IV push.
Foods to eat	Low: Bananas, potatoes, oranges, spinach, avocado. High: Apples, grapes, berries, rice, and cabbage.

3. Calcium (Ca²⁺)

Normal: 8.5–10.5 mg/dL

Category	What to know
Importance	Strong bones and teeth, muscle contractions, nerve function, blood clotting.
Hypo: Low calcium	Tingling around mouth, numbness, muscle spasms, tetany, seizures, positive Chvostek's and Trousseau's signs.
Hyper: High calcium	Muscle weakness, constipation, kidney stones, confusion, bone pain.
Nursing interventions	Monitor calcium and ECG. Low calcium may require calcium or vitamin D replacement. High calcium may require hydration and prescribed medications.
Foods to eat	Low: Milk, yogurt, cheese, fortified foods. High: Avoid excess calcium supplements and follow prescribed dietary restrictions.

4. Magnesium (Mg²⁺)

Normal: 1.5–2.5 mEq/L

Category	What to know
Importance	Nerve function, muscle relaxation, heart rhythm.
Hypo: Low magnesium	Tremors, muscle cramps, increased reflexes, seizures, irregular heartbeat.
Hyper: High magnesium	Low blood pressure, slow heart rate, decreased reflexes, drowsiness, respiratory depression.
Nursing interventions	Monitor magnesium, reflexes, heart rate, and respirations. Low magnesium may require replacement. High magnesium may require stopping magnesium sources and prescribed calcium gluconate.
Foods to eat	Low: Nuts, seeds, spinach, beans, whole grains. High: Follow prescribed magnesium restrictions; avoid magnesium supplements and certain laxatives.

5. Chloride (Cl⁻)

Normal: 98–106 mEq/L

Category	What to know
Importance	Fluid balance, acid-base balance, stomach acid production.
Hypo: Low chloride	Muscle cramps, weakness, confusion, shallow breathing.
Hyper: High chloride	Weakness, excessive thirst, dehydration, deep or rapid breathing.
Nursing interventions	Monitor chloride, fluid balance, and acid-base levels. Treat the underlying cause. Fluid or electrolyte replacement may be prescribed.
Foods to eat	Low: Broth, tomatoes, lettuce, celery. High: Fresh fruits and vegetables; limit salty and processed foods.

6. Phosphorus (Phosphate)

Normal: 2.5–4.5 mg/dL

Category	What to know
Importance	Energy production (ATP), bones, teeth, muscle function.
Hypo: Low phosphorus	Muscle weakness, fatigue, bone pain, confusion, respiratory muscle weakness.
Hyper: High phosphorus	Muscle cramps, tingling, calcium deposits, low-calcium symptoms.
Nursing interventions	Monitor phosphorus and calcium. Low phosphorus may require phosphate replacement. High phosphorus may require phosphate binders and dietary restrictions.
Foods to eat	Low: Milk, cheese, meat, eggs, beans, nuts. High: Apples, berries, rice, and lower-phosphorus foods.