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About this deck
This is a free 20-card deck for the nursing lab values that come up on almost every exam. Five cards cover electrolytes, three cover blood counts, two cover coagulation, three cover kidney function and six cover arterial blood gases, plus a blood glucose card. The front of each card names a lab. The back gives a typical adult range and what an abnormal value tells you to watch for. Ranges vary by lab and textbook, so check your own program's list. This deck is exam practice, not medical guidance.
All 20 cards in this deck
The full deck is listed below, front and back. Answers stay collapsed until you open them, so you can quiz yourself as you scroll.
Sodium (Na): typical adult range, and what does a change mean?
135 to 145 mEq/L. Sodium mostly reflects water balance in the body. Low sodium (hyponatremia) can cause headache, confusion and, if severe, seizures. High sodium (hypernatremia) goes with thirst, dry mucous membranes and confusion, often from dehydration. Watch neuro status, fluid intake and output, and daily weight.
Potassium (K): typical adult range, and why is it high-stakes?
3.5 to 5.0 mEq/L. The range is narrow and both ends affect the heart. Low potassium causes weakness, cramps, constipation and arrhythmias, with flat T waves and U waves on the ECG. High potassium causes weakness and arrhythmias, with peaked T waves and a wide QRS. Watch heart rhythm. A hemolyzed blood sample can read falsely high.
Calcium (total): typical adult range, and the high and low signs?
8.5 to 10.5 mg/dL. Low calcium: numbness and tingling around the mouth, muscle cramps, tetany, and positive Chvostek and Trousseau signs. High calcium: bones, stones, groans and moans, meaning bone pain, kidney stones, constipation and abdominal pain, and confusion. Low albumin lowers total calcium, and ionized calcium is the active form.
Magnesium (Mg): typical adult range, and what does a change mean?
1.5 to 2.5 mg/dL. Low magnesium often travels with low potassium and low calcium, and brings tremor, twitching and arrhythmias. High magnesium is usually seen with kidney impairment, because the kidneys clear it, and brings loss of deep tendon reflexes, drowsiness, low blood pressure and slowed breathing. Check reflexes and respiratory rate.
Phosphorus (phosphate): typical adult range, and its link to calcium?
2.5 to 4.5 mg/dL. Phosphorus and calcium have an inverse, seesaw relationship: when one goes up the other tends to go down. High phosphorus is most often seen with kidney disease. Low phosphorus causes muscle weakness and can happen when a malnourished person restarts eating (refeeding).
Hemoglobin and hematocrit: typical adult ranges and the rule of three?
Hemoglobin: about 13.5 to 17.5 g/dL in men and 12 to 16 g/dL in women. Hematocrit: about 41 to 53 percent in men and 36 to 46 percent in women. The rule of three says hematocrit is roughly three times hemoglobin. Low values mean anemia: fatigue, pallor, shortness of breath, fast heart rate. High values suggest dehydration or too many red cells. After sudden bleeding the values can look normal at first.
White blood cell count (WBC): typical range, and what do highs and lows mean?
About 4,500 to 11,000 per mm3. A high count (leukocytosis) points to infection, inflammation or stress, and some medications such as steroids raise it. A low count (leukopenia) raises infection risk. For neutrophils specifically, an absolute neutrophil count under 1,500 is neutropenia and under 500 is severe. Watch temperature and infection signs.
Platelets: typical range, and what is the risk when they are low?
About 150,000 to 400,000 per mm3 (some labs go up to 450,000). Low platelets (thrombocytopenia) raise bleeding risk: petechiae, easy bruising, bleeding gums and nosebleeds. The risk climbs as the count falls, and counts below about 20,000 carry a risk of spontaneous bleeding. Watch for bleeding and protect the skin and mucous membranes.
PT and INR: typical ranges, and which drug are they linked to?
PT is about 11 to 13.5 seconds. INR is about 0.8 to 1.1 in people who are not on anticoagulants. PT and INR are used to monitor warfarin, and the target INR is set by the prescriber for each patient (many common targets are 2.0 to 3.0). A high INR means blood clots more slowly: watch for bruising and blood in urine or stool. Liver disease and low vitamin K also raise PT.
aPTT: typical range, and which drug is it linked to?
About 25 to 35 seconds, though labs differ and some run 30 to 40. aPTT is used to monitor heparin, with a target often expressed as 1.5 to 2.5 times the control value, set by protocol and the prescriber. A prolonged aPTT means a bleeding risk. A quick way to remember it: warfarin goes with PT and INR, heparin goes with aPTT.
BUN: typical range, and what does a high or low value suggest?
10 to 20 mg/dL. High BUN suggests dehydration, reduced kidney function, GI bleeding or a high-protein intake. Low BUN is seen with liver disease, malnutrition and overhydration. The BUN-to-creatinine ratio is normally about 10:1 to 20:1, and a ratio above that points toward dehydration or poor blood flow to the kidneys.
Creatinine: typical range, and why is it a better kidney marker than BUN?
About 0.6 to 1.2 mg/dL, lower in women and higher in men because it tracks muscle mass. The body makes creatinine at a steady rate and the kidneys clear it, so it is less affected by diet and hydration than BUN. A rising creatinine means the kidneys are clearing less. As a rough rule, a doubled creatinine means about half the kidney function.
eGFR: what is normal, and what is the chronic kidney disease cutoff?
An eGFR of 90 or more mL/min/1.73 m2 is normal. An eGFR below 60 for three months or longer points to chronic kidney disease, and below 15 is kidney failure (stage 5). eGFR is calculated from creatinine, age and sex, so it estimates how well the kidneys filter blood.
ABG: what is the normal arterial pH, and what do high and low mean?
7.35 to 7.45. Below 7.35 is acidosis, and above 7.45 is alkalosis. The pH tells you which way the blood is leaning. Then check PaCO2 and bicarbonate to see whether the lungs (respiratory) or the kidneys and metabolism (metabolic) explain it.
ABG: PaCO2 range, and what do high and low mean?
35 to 45 mmHg. This is the respiratory part, and CO2 acts as an acid. A high PaCO2 means respiratory acidosis, from breathing too little (hypoventilation), as with sedation or COPD. A low PaCO2 means respiratory alkalosis, from breathing too fast, as with pain, anxiety or fever. Watch breathing rate and effort.
ABG: bicarbonate (HCO3) range, and what do high and low mean?
22 to 26 mEq/L. This is the metabolic part, and bicarbonate acts as a base. A low HCO3 means metabolic acidosis, as in diabetic ketoacidosis, severe diarrhea or kidney failure. A high HCO3 means metabolic alkalosis, as with prolonged vomiting or nasogastric suction.
ABG: PaO2 and oxygen saturation ranges?
PaO2 is 80 to 100 mmHg and SaO2 is 95 to 100 percent. Low values mean hypoxemia: restlessness, confusion, fast breathing and a fast heart rate. A pulse oximeter reading (SpO2) estimates SaO2 without a blood draw. Some patients with chronic lung disease live with lower baselines, so compare with their own normal.
How do you read an ABG with ROME?
First look at pH: acidosis or alkalosis. Then ROME: in Respiratory problems the pH and CO2 move in Opposite directions (low pH with high CO2 is respiratory acidosis). In Metabolic problems the pH and HCO3 move the Equal way (low pH with low HCO3 is metabolic acidosis). Whichever one matches the pH is the cause.
ABG compensation: uncompensated, partially compensated and fully compensated?
Uncompensated: pH is abnormal and only one of CO2 or HCO3 is off. Partially compensated: pH is still abnormal, but both CO2 and HCO3 are off, because the other system has started to respond. Fully compensated: pH is back in the normal range, but CO2 and HCO3 are both still abnormal. The lungs respond within minutes to hours, the kidneys over days.
Blood glucose and A1c: normal values and the diabetes cutoffs?
Fasting glucose is 70 to 99 mg/dL. Below 70 is hypoglycemia: shakiness, sweating, hunger, confusion and a fast heartbeat. By American Diabetes Association criteria, a fasting level of 126 or higher on two tests points to diabetes, and 100 to 125 is prediabetes. A1c reflects the average over about 3 months: below 5.7 percent is normal, 5.7 to 6.4 is prediabetes, and 6.5 or higher is diabetes.
What the 20 lab values flashcards cover
The deck follows the order most nursing courses teach labs in. Electrolytes come first: sodium, potassium, calcium, magnesium and phosphorus. Next are the blood counts that matter most: hemoglobin and hematocrit together, white blood cells and platelets. Then coagulation, with PT and INR on one card and aPTT on the next. Kidney function has three cards for BUN, creatinine and eGFR. Arterial blood gases get six cards: pH, PaCO2, bicarbonate, oxygen, the ROME rule for reading a result and the three levels of compensation. The last card is blood glucose with the A1c cutoffs.
Every card has the same shape. The front names the lab. The back gives a typical adult reference range, then what a low or high value points to and what a nurse watches or checks next, such as heart rhythm for potassium or bleeding signs for platelets. That pairing matches how exams ask: not what is the number, but what does this number mean for your patient.
A note on ranges. Labs, hospitals and textbooks publish slightly different reference ranges, and children, older adults and pregnant patients have their own. The numbers here are typical adult values from common nursing references. On the job, use the range printed on the lab report. For an exam, use the values your program teaches. This deck is exam practice, not medical guidance, and it does not include treatment or dosing.
How to memorize nursing lab values
Do not try to learn forty numbers in a row. Group them and attach a meaning to each one. Potassium is 3.5 to 5.0, and the key fact is not the range but that both ends threaten the heart. Calcium low means tingling and tetany, and calcium high means bones, stones, groans and moans. Phosphorus and calcium move in opposite directions like a seesaw. Hematocrit is roughly three times hemoglobin. PT and INR go with warfarin, aPTT goes with heparin.
For each card, say the range out loud before you flip, then say what a low and a high value would look like at the bedside. If you can name the symptom or the monitoring step, you will recognize it in a case question even when the number is not written out. Cards you miss come back in the next round, so be strict with yourself.
For arterial blood gases, learn the order. Look at pH first to see acidosis or alkalosis, then ask whether PaCO2 or bicarbonate explains it. ROME helps: in respiratory problems the pH and CO2 move in Opposite directions, and in Metabolic problems the pH and bicarbonate move the Equal way.
How StudyPDF builds decks from your own lab values sheet
Twenty cards cover the core values. Your program may use a different range list, add cardiac markers, liver enzymes or lipid panels, or expect you to know values in SI units.
Upload your own lecture slides, lab values handout or nursing notes to StudyPDF, press New material and pick flashcards, and the deck is built from that exact material, so the ranges match what you are tested on. You do not have to upload anything to start: you can also just name a topic, like liver function tests or cardiac markers, and Bo sets it up with its key concepts, so you can build a deck on it. Every card points back to the page it came from. Starting is free.
Written by the StudyPDF team. Last updated August 19, 2026.
Good to know
Are these nursing lab values flashcards free?
Yes. All 20 cards are free to flip through as often as you like, and playing runs fully in your browser. A free StudyPDF account is needed to download the deck as a PDF or to build bigger decks from your own notes.
Are these normal ranges the same as my textbook?
They may differ a little. Labs, hospitals and textbooks publish slightly different reference ranges, and children and older adults have their own. These cards use typical adult values. For an exam, learn the numbers your program teaches. On the job, use the range printed on the lab report.
Who made these cards, and is this medical advice?
The StudyPDF team wrote every card. The deck is exam practice, not medical guidance. It covers reference ranges and what an abnormal value means for monitoring, and it leaves out treatment and dosing, so your course materials and current clinical sources always come first.
What is the best way to memorize lab values for nursing school?
Group the values by panel and attach a meaning to each number, such as what a low and a high potassium do to the heart. Say the range out loud before you flip a card, then say what you would see at the bedside. Review missed cards the next day, and use a mnemonic like ROME for blood gases.
Need more than a sampler?
Upload your own prep book, slides or notes and Bo builds full-length practice tests from your exact materials, tracks which concepts you keep missing and targets your weak spots. Free to start.