← CNA Exam: Nutrition & Elimination

CNA Certified Nursing Assistant Exam Study Guide

Key concepts, definitions, and exam tips organized by topic.

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CNA Exam Study Guide: Nutrition & Elimination


Overview

This study guide covers the essential knowledge CNAs need for assisting residents with nutrition, managing special diets, monitoring fluid balance, and supporting urinary and bowel elimination. These topics are heavily tested on the CNA exam and are fundamental to daily patient care. Mastering these concepts ensures resident safety, dignity, and optimal health outcomes.


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Section 1: Nutrition & Feeding Assistance


Key Concepts

Proper feeding assistance is critical to preventing aspiration — one of the most serious risks during mealtimes. The CNA's role is to support safe eating while respecting resident rights and preferences.


Positioning for Meals

  • • Always place resident in an upright, 90-degree sitting position before meals
  • • This position uses gravity to help food move safely down the esophagus
  • • Never feed a resident who is lying flat or reclined at less than 45 degrees

    • Feeding Technique

  • • Wait for complete swallowing before offering the next bite
  • • Offer small, manageable bites
  • • Alternate between foods and fluids when appropriate
  • • Match the pace to the resident's comfort level — never rush
  • • Engage the resident in conversation to maintain a calm, dignified atmosphere

    • Recognizing & Reporting Problems

    Immediately report any of the following to the nurse:

  • • Coughing, choking, or gagging during meals
  • • Gurgling or wet-sounding voice after swallowing
  • • Food or liquid coming out of the nose
  • • Facial grimacing or pain with swallowing
  • • Repeated throat clearing

    • Resident Refusal to Eat

  • • Residents have the legal right to refuse food
  • • Do NOT force or coerce a resident to eat
  • • Document the refusal accurately, including what was offered
  • • Report to the nurse so the care plan can be re-evaluated
  • • Explore reasons for refusal (pain, nausea, food preferences, depression)

    • Key Terms

  • • Aspiration — Inhalation of food, liquid, or secretions into the lungs
  • • Aspiration pneumonia — Lung infection caused by aspirated material
  • • Dysphagia — Difficulty swallowing; significantly increases aspiration risk
  • • Bolus — A single, formed portion of food ready to be swallowed

    • ⚠️ Watch Out For

    > Exam Trap: CNAs sometimes confuse "dysphagia" with "dysphasia" (a speech/language disorder). Know that dysphagia = swallowing difficulty and is a key safety concern during meals.


    > Common Mistake: Never tilt a resident's head back to feed them — this actually increases aspiration risk. A chin-tuck position is often safer for residents with dysphagia.


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    Section 2: Special Diets & Dietary Needs


    Key Concepts

    Many residents require medically prescribed diets based on their health conditions. CNAs do not prescribe diets but must understand, follow, and enforce them. Serving the wrong diet can be dangerous.


    Common Diet Types


    | Diet Type | Characteristics | Ordered For |

    |---|---|---|

    | Regular | No restrictions | Residents without dietary needs |

    | Mechanical Soft | Soft, moist, easy to chew; no hard/raw foods | Poor dentition, jaw weakness |

    | Pureed | Blended smooth, no lumps or chunks | Severe dysphagia, inability to chew |

    | Thickened Liquids | Nectar, honey, or pudding consistency | Dysphagia; slows liquid flow to control swallowing |

    | Low-Sodium | Restricted salt and salty foods | Heart disease, hypertension, edema |

    | Diabetic/ADA | Controlled calories and carbohydrates | Diabetes mellitus |

    | Low-Fat/Low-Cholesterol | Reduced fat content | Heart disease, high cholesterol |


    Thickened Liquid Consistency Levels

  • • Nectar thick — Slightly thicker than water; pours like nectar
  • • Honey thick — Thicker; drizzles like honey
  • • Pudding thick — Spoon-thick; does not pour

    • Low-Sodium Diet: Foods to Avoid

  • • Canned soups, vegetables, and meats
  • • Processed and packaged foods
  • • Pickled foods (pickles, olives)
  • • Deli/processed meats (salami, hot dogs)
  • • Added table salt

    • Diabetic (ADA) Diet

  • • Controlled caloric intake (e.g., 1,800 calories/day)
  • • Consistent carbohydrate distribution across meals
  • • If a diabetic resident requests extra food outside their plan:

    • 1. Politely decline

    2. Explain the diet is medically prescribed

    3. Report the request to the nurse


    Key Terms

  • • Mechanical soft diet — Foods that are tender and moist but retain some texture
  • • Pureed diet — Foods processed to a completely smooth consistency
  • • ADA diet — American Diabetes Association diet; calorie and carbohydrate controlled
  • • Edema — Swelling caused by excess fluid in tissues; worsened by high sodium intake
  • • Dysphagia diet — Specially modified textures/consistencies for swallowing disorders

    • ⚠️ Watch Out For

    > Exam Trap: A mechanical soft diet is not the same as a pureed diet. Mechanical soft foods still have texture and shape — they are just easier to chew. Pureed foods are fully blended with no recognizable texture.


    > Key Rule: The CNA never decides to change or modify a resident's diet on their own. Always follow the care plan and consult the nurse with any concerns or requests.


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    Section 3: Fluid Balance & Intake/Output (I&O)


    Key Concepts

    Maintaining fluid balance is essential to organ function and overall health. CNAs play a vital role in measuring, recording, and reporting fluid intake and output to catch problems early.


    I&O Fundamentals

  • • I&O = Intake and Output
  • • Intake includes: Oral fluids, IV fluids, tube feedings, ice chips (record as half the volume)
  • • Output includes: Urine, emesis (vomiting), wound drainage, diarrhea
  • • Recorded every shift in milliliters (mL)

    • Essential Conversion

    > 30 mL = 1 ounce (oz)


    | Common Container | Approximate Volume |

    |---|---|

    | 8 oz cup | 240 mL |

    | 4 oz juice glass | 120 mL |

    | 6 oz soup bowl | 180 mL |

    | 12 oz water pitcher | 360 mL |


    Dehydration: Signs & Symptoms

  • • Dry mouth and cracked lips
  • • Sunken eyes
  • • Decreased skin turgor (skin tents when pinched)
  • • Dark, concentrated urine (amber/orange color)
  • • Low urine output (oliguria)
  • • Confusion or dizziness
  • • Rapid, weak pulse

    • Fluid Restriction

  • • The nurse manages the overall restriction plan
  • • The CNA enforces it by offering only allowed amounts per shift
  • • Document accurately and completely
  • • Report if the resident is requesting more fluids or drinking outside the plan

    • Normal vs. Abnormal Urine Output

  • • Normal adult output: approximately 30 mL/hour or more
  • • Oliguria (<30 mL/hour) = report to nurse immediately
  • • Anuria (no urine output) = report to nurse immediately

    • Key Terms

  • • Intake — All fluids entering the body
  • • Output — All fluids leaving the body
  • • Oliguria — Abnormally decreased urine output (<30 mL/hour)
  • • Anuria — Absence of urine production
  • • Dehydration — Insufficient fluid in the body
  • • Fluid restriction — A medically ordered limit on daily fluid intake
  • • Skin turgor — The skin's elasticity; poor turgor indicates dehydration

    • ⚠️ Watch Out For

    > Exam Trap: On the exam, you may be asked to calculate fluid intake. Remember 1 oz = 30 mL. Practice converting ounces to mL for common containers.


    > Common Mistake: Ice chips count as fluid! Record them as half their volume (e.g., 4 oz of ice = 2 oz = 60 mL of fluid).


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    Section 4: Urinary Elimination


    Key Concepts

    CNAs assist with urinary elimination through toileting, catheter care, and careful observation. Protecting resident dignity and preventing infection are the top priorities.


    Urinary Catheter Care

    Steps for emptying a catheter drainage bag:

    1. Perform hand hygiene and apply gloves

    2. Open the drain valve at the bottom of the bag

    3. Empty urine into a graduated measuring container (do not let drain touch container)

    4. Record the amount in mL

    5. Close the drain valve

    6. Clean the drain port with an alcohol wipe

    7. Remove gloves, perform hand hygiene, and document


    Cleaning the catheter (pericare):

  • • Clean from the meatus (urethral opening) outward, moving away from the body
  • • This prevents bacteria from being pushed into the urinary tract
  • • Use a clean stroke each time; never wipe back toward the body

    • Abnormal Urine: What to Report Immediately

    | Observation | Possible Significance |

    |---|---|

    | Blood in urine (hematuria) | Trauma, infection, kidney problem |

    | Cloudy urine | Possible urinary tract infection (UTI) |

    | Foul or strong odor | Possible UTI or dehydration |

    | Dark amber or orange urine | Dehydration or medication effect |

    | Sediment or particles | Infection or kidney stones |

    | Burning/pain complaints | UTI symptoms |

    | No output for several hours | Obstruction or kidney failure |


    Urinary Incontinence

  • • Definition: Involuntary (uncontrolled) loss of urine
  • • CNA Response:

    • - Respond without judgment or criticism — protect dignity always

    - Promptly clean and dry the resident

    - Change soiled clothing and linens

    - Check skin for signs of breakdown (redness, irritation)

    - Document the episode

    - Never make the resident feel embarrassed or shamed


    Key Terms

  • • Urinary catheter — A tube inserted into the bladder to drain urine
  • • Foley catheter — Indwelling (stays in place) urinary catheter
  • • Meatus — The external urethral opening
  • • Hematuria — Blood in the urine
  • • Urinary incontinence — Involuntary loss of urine
  • • UTI (Urinary Tract Infection) — Infection in the urinary system; common in catheterized patients
  • • Urinary retention — Inability to empty the bladder completely

    • ⚠️ Watch Out For

    > Exam Trap: Always clean the catheter from clean to dirty — from the body outward. Never wipe back toward the meatus after cleaning distally.


    > Dignity Alert: The CNA exam frequently tests professional, non-judgmental responses to incontinence. Always respond with respect and compassion, never frustration or blame.


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    Section 5: Bowel Elimination


    Key Concepts

    Bowel elimination involves careful observation, prevention of complications, and respectful, timely assistance. CNAs must know what is normal, what to report, and how to prevent common problems like constipation.


    Constipation: Prevention & Interventions


    Definition: Difficulty passing hard, dry stools; typically fewer than 3 bowel movements per week


    CNA interventions within scope of practice:

  • • Encourage adequate fluid intake (softens stool)
  • • Promote ambulation and activity as allowed by the care plan
  • • Respond promptly when a resident requests toileting assistance
  • • Offer foods high in fiber (as allowed by diet plan)
  • • Provide privacy during bowel elimination (reduces inhibition)

    • Abnormal Bowel Observations: What to Report

    | Observation | Possible Significance |

    |---|---|

    | Black/tarry stools (melena) | Possible internal/upper GI bleeding |

    | Bright red blood in stool | Lower GI bleeding, hemorrhoids |

    | White or clay-colored stool | Liver or bile duct problem |

    | Diarrhea | Infection, medication side effect |

    | No BM for 3+ days | Constipation or impaction |

    | Liquid stool with no normal BM | Possible fecal impaction |

    | Rectal pain complaints | Hemorrhoids, fissure, impaction |

    | Extremely hard, pellet-like stool | Severe constipation |


    Fecal Impaction

  • • Definition: A large, hard mass of stool lodged in the rectum that cannot be passed
  • • Signs to recognize and report:

    • - No formed stool for several days

    - Liquid stool or mucus leaking around the blockage (overflow diarrhea)

    - Abdominal distension and discomfort

    - Complaints of rectal fullness or pressure

  • • CNA role: Report to the nurse immediately — do not attempt to manually remove an impaction (outside CNA scope of practice)

    • Colostomy Care

  • • Colostomy: A surgical opening (stoma) in the abdominal wall through which fecal matter exits into a collection pouch
  • • CNA responsibilities:

    • - Empty the pouch when it is 1/3 to 1/2 full

    - Change the pouch according to the care plan

    - Inspect the stoma for abnormalities

    - Clean skin around the stoma gently

    - Report any redness, irritation, bleeding, or unusual output to the nurse


    Normal vs. Abnormal Stoma Appearance

  • • Normal stoma: Moist, pink to red in color, slightly raised
  • • Report immediately: Pale, dark purple/black, bleeding, unusual odor, retraction, or skin breakdown around the stoma

    • Bedpan Use

  • • Position the resident correctly for comfort and safety
  • • Provide privacy for approximately 5 minutes
  • • Ensure the call light is within reach
  • • Never leave a resident on a bedpan for an extended time — prolonged pressure causes skin breakdown and discomfort
  • • Check back promptly and respond quickly when signaled

    • Key Terms

  • • Constipation — Infrequent or difficult passage of hard, dry stools
  • • Fecal impaction — A large hardened stool mass in the rectum
  • • Diarrhea — Frequent, loose, watery stools
  • • Melena — Black, tarry stool indicating upper GI bleeding
  • • Colostomy — Surgical opening from the colon to the abdominal wall
  • • Stoma — The external opening of a colostomy
  • • Peristalsis — Wave-like muscle contractions that move stool through the bowel
  • • Bowel motility — The movement of the intestines; stimulated by activity and fluids

    • ⚠️ Watch Out For

    > Exam Trap: Liquid or watery stool does not always mean diarrhea — it can actually be a sign of fecal impaction, where liquid leaks around a hardened mass. This is a serious condition requiring immediate reporting.


    > Scope of Practice Alert: CNAs never administer enemas (unless specifically trained and permitted per state guidelines) or manually disimpact stool. These are nursing interventions. Report and document; do not act beyond your scope.


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    Quick Review Checklist ✅


    Use this checklist to confirm you have mastered all key points before your exam:


    Nutrition & Feeding

  • • [ ] Position resident at 90 degrees before meals
  • • [ ] Wait for complete swallow before offering next bite
  • • [ ] Know that dysphagia = swallowing difficulty and increases aspiration risk
  • • [ ] Recognize and immediately report coughing, choking, and gagging at mealtimes
  • • [ ] Respect resident's right to refuse food; document and report

    • Special Diets

  • • [ ] Know the difference between mechanical soft and pureed diets
  • • [ ] Understand why thickened liquids are ordered (aspiration prevention)
  • • [ ] Know foods restricted on a low-sodium diet
  • • [ ] Never change a resident's diet without nurse/care plan direction
  • • [ ] Report and defer special food requests to the nurse

    • Fluid Balance &

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