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Hypokalemia — NCLEX Cheat Sheet

Q: What are the priority nursing interventions for Hypokalemia?

Replace potassium — oral if mild; IV for severe (NEVER IV push) at no more than 10 mEq/hr. Always dilute IV potassium and use a pump; check that urine output is adequate first. Put the client on a cardiac monitor and watch for dysrhythmias. Hold further potassium-wasting diuretics and notify the provider.

Q: What are the warning signs of Hypokalemia a nurse must report?

K⁺ < 2.5 mEq/L or any dysrhythmia — notify provider immediately. Never give potassium IV push or as a bolus — it can cause fatal cardiac arrest.

Q: What do I need to know about Hypokalemia for the NCLEX?

Muscle weakness, leg cramps, and fatigue — severe loss causes flaccid paralysis. Decreased GI motility → hypoactive bowel sounds, constipation, paralytic ileus. ECG changes: flattened T waves, ST depression, and prominent U waves. Increases the risk of digoxin toxicity — low K⁺ potentiates digoxin.

Q: What patient teaching is important for Hypokalemia?

Eat potassium-rich foods: bananas, oranges, potatoes, avocado, spinach. If on a loop/thiazide diuretic, report muscle weakness or palpitations.

K+ < 3.5 mEq/L

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👤 By the CinnaRN Clinical Content Team 🕐 Updated 2026-08-23 🏷️ Physiological Adaptation 🔖 Free to read, print, and share

Also known as: low potassium · low K · potassium deficit

Hypokalemia — medical illustration. Illustration: Open Courses, TEI of Athens via Wikimedia Commons, CC BY-SA 3.0.

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Use this quick-reference guide to spot, treat, and prevent Hypokalemia on the NCLEX. Keep it handy during review and on exam day!

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📒 The 1-minute cheat sheet

⚠️ Causes

Loop/thiazide diuretics, ↑ losses
Vomiting, diarrhea, NG suction
Insulin, alkalosis shift K+ in

🩺 Signs

Muscle weakness, leg cramps
↓ bowel sounds, ileus, constipation
ECG: flat T, U wave, ST↓

✅ Do

Give K+ slow → never IV push
Max 10 mEq/hr, on pump, diluted
↑ K+ diet: banana, potato, OJ

🚩 Report

Dig toxicity risk if low K+
Check renal/UO before replacing

📚 Hypokalemia — full study notes

The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.

Hypokalemia is a serum potassium below 3.5 mEq/L. Potassium is the major intracellular cation and is essential for normal cardiac, neuromuscular, and smooth-muscle function, so a deficit shows up first as muscle weakness and cardiac irritability. Common causes are diuretics (loop/thiazide), vomiting, diarrhea, NG suction, and insulin or alkalosis shifting K⁺ into cells.

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Key points

Understand these first

Muscle weakness, leg cramps, and fatigue — severe loss causes flaccid paralysis
Decreased GI motility → hypoactive bowel sounds, constipation, paralytic ileus
ECG changes: flattened T waves, ST depression, and prominent U waves
Increases the risk of digoxin toxicity — low K⁺ potentiates digoxin
Often paired with metabolic alkalosis (vomiting, diuretics)

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Nursing priorities

What to do, in order

Replace potassium — oral if mild; IV for severe (NEVER IV push) at no more than 10 mEq/hr
Always dilute IV potassium and use a pump; check that urine output is adequate first
Put the client on a cardiac monitor and watch for dysrhythmias
Hold further potassium-wasting diuretics and notify the provider

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Red flags — report now

Escalate immediately

K⁺ < 2.5 mEq/L or any dysrhythmia — notify provider immediately
Never give potassium IV push or as a bolus — it can cause fatal cardiac arrest

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Labs & values

Numbers to know

Serum potassium 3.5–5.0 mEq/L (hypokalemia < 3.5)

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Patient teaching

What patients must know

Eat potassium-rich foods: bananas, oranges, potatoes, avocado, spinach
If on a loop/thiazide diuretic, report muscle weakness or palpitations

❓ Hypokalemia: NCLEX FAQs

What are the priority nursing interventions for Hypokalemia?

Replace potassium — oral if mild; IV for severe (NEVER IV push) at no more than 10 mEq/hr. Always dilute IV potassium and use a pump; check that urine output is adequate first. Put the client on a cardiac monitor and watch for dysrhythmias. Hold further potassium-wasting diuretics and notify the provider.

What are the warning signs of Hypokalemia a nurse must report?

K⁺ < 2.5 mEq/L or any dysrhythmia — notify provider immediately. Never give potassium IV push or as a bolus — it can cause fatal cardiac arrest.

What do I need to know about Hypokalemia for the NCLEX?

Muscle weakness, leg cramps, and fatigue — severe loss causes flaccid paralysis. Decreased GI motility → hypoactive bowel sounds, constipation, paralytic ileus. ECG changes: flattened T waves, ST depression, and prominent U waves. Increases the risk of digoxin toxicity — low K⁺ potentiates digoxin.

What patient teaching is important for Hypokalemia?

Eat potassium-rich foods: bananas, oranges, potatoes, avocado, spinach. If on a loop/thiazide diuretic, report muscle weakness or palpitations.

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