FREE CHT Study Guide 2026: A Complete BONENT Hemodialysis Walkthrough

This free CHT study guide walks through the highest-yield content the BONENT Certified Hemodialysis Technologist/Technician (CHT) exam tests, organized by the five official BONENT domains — Patient Care, Machine Technology, Water Treatment, Infection Control, and Education & Professional Development.^[1]

It is interactive, not a wall of text: every domain has worked clinical scenarios, labeled diagrams of the blood circuit and the water-treatment train, data tables, and built-in flashcards — taught the way the CHT is actually tested, with most items written as scenario and judgment questions rather than rote recall.^[1]

Read it domain by domain, then round out your prep with our practice questions and flashcards. The CHT is one of the two main dialysis-technician credentials; under the CMS Conditions for Coverage, patient-care technicians are expected to be certified within 18 months of hire.^[2]

CHT Exam Snapshot

Patient Care is nearly half the exam (45%), so dialysis principles, vascular access, fluid management, and complications deserve the most study time. Infection Control (18%) and Water Treatment (15%) are next, followed by Machine Technology (12%) and Education & Professional Development (10%).^[1]

Percentages are each domain’s published share of the 150 items.^[1] This guide teaches all five domains as five study modules, so the structure matches the BONENT content outline exactly.

How the CHT Exam Is Built

The CHT exam follows the BONENT Examination Content Outline, which groups every item into five domains drawn from the day-to-day work of a hemodialysis technician. This guide teaches all five as study modules, so the structure matches the outline exactly.^[1]

• Patient Care (45%) — evaluating the patient before, during, and after treatment: fluid management, vital signs and access assessment, dialysis principles, complications, and documentation. The hands-on core of the role.
• Infection Control (18%) — a clean and safe environment, dialysis precautions, bloodborne pathogens, and isolation procedures.
• Water Treatment (15%) — the components and design of the water system, maintaining and disinfecting it, and monitoring quality against AAMI standards.
• Machine Technology (12%) — maintaining and setting up the dialysis machine, safety checks, alarms, and evaluating machine operation.
• Education & Professional Development (10%) — educating patients, professional growth and ethics, documentation, quality, and communication.

Because the technician works within a defined scope of practice under RN supervision — operating equipment and delivering the prescribed treatment, not diagnosing or changing the prescription — many items ask what you would do in a clinical situation rather than just recall a fact.^[1]

Patient Care

Patient Care is 45% of the exam — nearly half.^[1] It is the hands-on heart of dialysis: how the treatment removes wastes and fluid, how the vascular access works and is cared for, how to manage fluid status, and how to recognize and respond to complications.

Dialysis Principles

Hemodialysis replaces two jobs of the failed kidney: clearing wastes and removing excess fluid. Inside the dialyzer, blood flows on one side of a thin semipermeable membrane and dialysate flows on the other, in opposite directions (countercurrent) to keep the gradient strong along the whole length.

Three transport mechanisms do the work. Diffusion moves solute wastes — urea, creatinine, potassium — from blood (high concentration) to dialysate (low or none), and it is how wastes are cleared.

Ultrafiltration moves water out of the blood under the transmembrane pressure gradient, and it is how fluid is removed to reach dry weight. Convection is solute carried along with that water, removing larger molecules. Osmosis plays a minor role.^[4]

Vascular Access & Cannulation

Every treatment needs a vascular access. The AV fistula — the patient’s own artery joined to a vein — is preferred for its long-term patency and low infection rate (the “Fistula First” principle); it matures over 6–12 weeks.

The AV graft (a synthetic bridge) is the second choice and is usable in about 2–3 weeks. The central venous catheter is the last resort because it carries the highest bloodstream-infection risk.^[5]

Before each use, assess the access by looking, listening, and feeling: palpate for a thrill and auscultate for a bruit, and inspect for redness, swelling, or drainage. No thrill or bruit suggests the access has clotted — do not cannulate, and report it. Never take a blood pressure or draw blood from the access arm.^[1]

Fluid Management & Dry Weight

Dry weight is the lowest post-dialysis weight a patient tolerates without symptoms of too much or too little fluid. The fluid to remove (the ultrafiltration goal) is roughly the pre-dialysis weight minus the dry weight. A large interdialytic weight gain forces a higher ultrafiltration rate and raises the risk of hypotension and cramps.^[5]

Blood pressure tracks fluid status: overload tends to raise it, over-removal drops it. That is why vital signs are taken before, during (per protocol), and after every treatment, and why an accurate pre- and post-weight matters.^[1]

Intradialytic Complications

Recognizing a complication and responding correctly is the most heavily tested clinical skill. Hypotension is the most common — treat it by lowering the ultrafiltration rate, placing the patient in Trendelenburg, and giving a saline bolus per protocol. Muscle cramps respond to the same UF reduction and saline.^[4]

Some complications are emergencies. An air embolism (air/foam in the line, chest pain, dyspnea) means clamp the venous line, stop the pump, place the patient left lateral with the head and chest down, and give oxygen.

Hemolysis (a cherry-red blood line, back/chest pain) means stop the pump, clamp the lines, and do not return the blood. Disequilibrium syndrome (headache, nausea, seizures) follows too-rapid urea removal, usually in a first treatment.^[4]

Labs, Adequacy & Medications

Failed kidneys cause predictable lab changes. Potassium is the most dangerous — it cannot be excreted between treatments, and high levels cause cardiac arrhythmias (the normal range is about 3.5–5.0 mEq/L). BUN and creatinine rise as wastes; phosphorus rises and drives bone disease; and patients develop anemia because the kidney makes too little erythropoietin.^[4]

Adequacy is measured by URR (percent drop in BUN, target ≥ 65%) and Kt/V (a clearance index, target ≥ 1.2). Common medications include erythropoiesis-stimulating agents and iron for anemia, phosphate binders taken with meals, and active vitamin D.^[5]

Machine Technology

Machine Technology is 12% of the exam.^[1] It covers the equipment that makes dialysis possible: the machine and the extracorporeal blood circuit, the dialysate and its conductivity, and the setup and safety checks that protect the patient.

The Dialysis Machine & Circuit

The extracorporeal circuit is the blood path outside the body. Blood leaves through the arterial line, passes an arterial pressure monitor, is moved by the roller blood pump (commonly 300–500 mL/min), receives heparin, flows through the dialyzer, passes a venous pressure monitor and the air/foam detector, and returns to the patient.^[4]

Several monitors protect the patient. A strongly negative arterial pressure suggests poor inflow; a high venous pressure suggests a venous-needle obstruction or a clotting circuit; the air/foam detector stops the pump and clamps the line if air is detected; and the blood leak detector alarms if blood crosses into the dialysate. Never bypass or tape over an alarm.^[1]

Dialysate & Conductivity

Dialysate is purified water mixed with acid and bicarbonate concentrate. The two concentrates are kept separate until the machine proportions them with water, because mixing them at full strength precipitates calcium and magnesium carbonate. The machine verifies the mix with conductivity and pH.^[4]

Conductivity is a safety check: it confirms the dialysate has the correct electrolyte concentration. A wrong conductivity means a wrong mix — dialysate that is too concentrated (hypertonic) or too dilute (hypotonic) can cause hemolysis and dangerous electrolyte shifts — so you do not begin treatment until it is correct, verified with an independent meter. Dialysate is also kept near body temperature, because overheated dialysate causes hemolysis.^[1]

Machine Setup & Safety Checks

Setting up the machine is a defined BONENT task: prepare the dialysis equipment (prime, rinse, fluid-delivery system), prepare auxiliary equipment (oxygen, glucometer, conductivity meter), prepare and verify the bicarbonate and acid solutions, and perform the required safety checks — conductivity, pH, and temperature — before a patient is connected. Alarms for the air detector, venous/arterial pressure, and blood leak are tested as part of setup.^[1]

Machine Technology also covers evaluating machine operation: rinse and disinfect the dialysis-delivery system on schedule, keep equipment-maintenance records for regulatory compliance, rotate equipment in the unit, and follow the maintenance procedures. Recognizing errors in blood and dialysate flow rates — and documenting daily equipment logs — falls here too.^[1]

Water Treatment

Water Treatment is 15% of the exam.^[1] A patient’s blood is exposed to roughly 120 or more liters of water per treatment across the membrane, so contaminants that are harmless to drink can be harmful. This domain covers the system that purifies that water, how it is maintained, and how its quality is monitored against AAMI standards.

The Water-Treatment Train

The water passes through a treatment train in order: a sediment filter, a softener (removes calcium/magnesium hardness), carbon tanks (remove chlorine and chloramine), reverse osmosis (the core step, rejecting most ions, bacteria, and endotoxin), optional deionization, and a distribution loop with no dead ends.^[6]

The carbon tanks are the most safety-critical stage — chloramine breakthrough causes hemolysis — so chlorine and chloramine are tested before each treatment day. Some systems also use ultraviolet light and an ultrafilter to control bacteria and endotoxin downstream.^[6]

Monitoring & AAMI Standards

AAMI sets limits on chemical and microbiological contaminants for both product water and dialysate. Technicians monitor total chlorine/chloramine, verify RO performance (percent rejection), and keep water-treatment records for regulatory and standard-setting compliance. A falling RO percent-rejection trend signals a degrading or fouling membrane that needs investigation.^[6]

The water-treatment system itself is disinfected on a schedule, and a residual-disinfectant test is performed before any patient is treated. Reprocessing equipment is quality-controlled per AAMI standards.^[6]

Dialyzer Reprocessing

Dialyzer reprocessing (reuse) cleans, tests, and disinfects a dialyzer so the samepatient can reuse it — it is never shared between patients and must carry that patient’s label. A reprocessed dialyzer must pass a fiber-bundle (total cell volume) test of at least 80% of original and an integrity (pressure/leak) test; a dialyzer that fails the leak test is discarded.^[6]

The single most critical patient-safety check is that residual germicide (sterilant) has been rinsed out and tested below the safe limit before the dialyzer is connected. Hepatitis B-positive patients are dialyzed in isolation and do not participate in reuse.^[3]

Infection Control

Infection Control is 18% of the exam — the second-largest domain.^[1] Dialysis patients have frequent vascular access and weakened immunity, so infection control and a safe physical environment are central to the technician’s job — infection is a leading cause of illness and death in this population.

Standard & Dialysis Precautions

Standard precautions treat every patient’s blood and body fluids as potentially infectious. The single most important measure is hand hygiene before and after every patient and after glove removal. Gloves are worn for every contact involving blood and changed between patients, and eye/face protection is added for any task that can splash blood — initiating or discontinuing treatment, handling lines, and cannulation.^[3]

The CDC adds dialysis-specific precautions: dedicate supplies to a single station, disinfect each station, machine, and chair between patients, and never share medication carts or vials between patients.^[3]

Bloodborne Pathogens & Isolation

The bloodborne pathogens of greatest concern are hepatitis B, hepatitis C, and HIV. Hepatitis B-positive patients are dialyzed in a separate room with dedicated machines, staff, and supplies (isolation) and are not in the reuse program, because HBV is highly transmissible. Susceptible patients (negative HBsAg and negative anti-HBs) are screened for HBsAg monthly so seroconversion is caught early, and the hepatitis B vaccine is recommended for them and offered free to at-risk staff.^[3]

Hepatitis C-positive patients are not routinely placed in a separate room — strict standard precautions are used instead. Used needles go directly into a closable, puncture-resistant, leak-proof, labeled sharps container — never recapped by hand. After any exposure (such as a needlestick), wash the site with soap and water, report immediately, and follow the exposure-control plan.^[3]

A Clean & Safe Environment

Follow all clean/dirty procedures to eliminate cross-contamination: wash machines, station areas, and chairs after each patient run, change gloves and perform hand hygiene between patients, and never allow the machine’s internal fluid pathways to simply air-dry between uses. A clean and safe environment also means clear walkways free of spills and clutter, secured tubing and cords, and an unobstructed emergency exit.^[3]

A new fever and chills during or shortly after treatment may signal an access-related bloodstream infection or a pyrogenic reaction, so the access is assessed and blood cultures are considered. Routine bacterial and endotoxin monitoring of the water and dialysate is itself an infection-control measure — it catches contamination before it causes a pyrogenic reaction.^[3]

Education & Professional Development

Education & Professional Development is 10% of the exam.^[1] It covers educating patients, the technician’s own professional growth and ethics, accurate documentation and quality, and communicating with patients and the care team.

Scope & the Care Team

A hemodialysis technician operates equipment and delivers the prescribed treatment under the supervision of a registered nurse. The role is to set up, monitor, and discontinue treatment, care for the access, and recognize and report complications — not to diagnose, prescribe, or independently change the dialysis prescription. A request to interpret labs and change the prescription is declined and referred to a licensed nurse or physician.^[1]

The multidisciplinary care team includes the nephrologist, the RN, the technician, the dietitian, and the social worker, each with defined responsibilities. Knowing where your role ends — and escalating to the nurse when a situation exceeds it — is itself a tested competency.^[1]

Patient Education

The technician reinforces patient education: discharge instructions on diet, fluid intake, and the medication regimen; the basic features of end-stage renal disease (complications, treatment, psychosocial impact, dietary restrictions); and the difference between acute renal failure (a sudden, often reversible loss that may need only temporary dialysis) and chronic kidney failure. Complex or individualized teaching is referred to the nurse or dietitian.^[4]

High-yield teaching points include taking phosphate binders with meals so they trap dietary phosphorus, limiting high-potassium foods, and the available treatment modalities — in-center and home hemodialysis, peritoneal dialysis, and transplant. Understanding normal kidney function — the glomerulus filters wastes and fluid while the kidney also makes hormones dialysis cannot replace — helps explain why patients still need ESAs and active vitamin D.^[5]

Documentation, Communication & QAPI

Documentation is the legal record of care and is required by the CMS Conditions for Coverage. Chart objectively and promptly, and document incidents (emergency, equipment/device, and patient-care events). To correct an error, draw a single line through it, write “error,” and initial and date it — never erase or use correction fluid, and never document care that was not performed.^[2]

Professional development also means staying current through continuing education and professional literature, maintaining professional ethics and boundaries (declining gifts and personal involvement), and participating in QAPI — quality assurance and performance improvement. Communication skills with staff — a teamwork approach, constructive working relationships, peer evaluations, protecting the confidentiality of patient and employee information, and helping orient new staff — round out the domain.^[1]

How to Use This Study Guide

Work through the guide one domain at a time. After each module, check it off in the contents to raise your exam-readiness score, then drill the same content in our free practice questions and flashcards — active recall and timed practice are what move knowledge into exam-day performance, especially on a scenario-heavy exam. If you are deciding between dialysis-technician credentials, our CCHT study guide covers the NNCC version of the same field.

• Weight your time by the percentages. Patient Care is nearly half the exam — start there and spend the most time on it.
• Think in scenarios. Many items ask what you would DO, so for every fact, ask “what’s the action?”
• Make the emergencies automatic. Air embolism, hemolysis, and severe hypotension responses should be reflexes.
• Connect the technical to the clinical. Chloramine and wrong conductivity cause hemolysis — the systems exist to protect the patient.
• Then prove it. When a domain feels easy, confirm it with our practice questions and flashcards.

Common questions CHT candidates search and get asked — each answered briefly and backed by an official source (BONENT, CMS, CDC, NIH, NKF, or AAMI). Tap any card to test yourself.

CHT Glossary

Key hemodialysis terms in one place. Hover any dotted term throughout the guide for its definition; the full list is below.

CHT

Certified Hemodialysis Technologist/Technician — the dialysis technician credential awarded by BONENT.

BONENT

Board of Nephrology Examiners Nursing and Technology — the certifying body that develops and awards the CHT credential.

hemodialysis

A treatment that filters wastes and removes excess fluid from the blood using a dialyzer when the kidneys have failed.

dialyzer

The 'artificial kidney' — a cartridge of semipermeable hollow fibers where blood and dialysate exchange wastes and water.

dialysate

The fluid (purified water plus acid and bicarbonate concentrate) on the other side of the dialyzer membrane that wastes diffuse into.

diffusion

Movement of solutes from blood to dialysate down a concentration gradient — the main way dialysis clears wastes.

osmosis

Movement of water across a semipermeable membrane toward the side with the higher solute concentration.

ultrafiltration

Removal of water from the blood driven by the transmembrane pressure gradient — how fluid is taken off to reach dry weight.

convection

Solute dragged along with water during ultrafiltration ('solvent drag'), which removes larger middle molecules.

transmembrane pressure

TMP — the pressure difference across the dialyzer membrane that governs the ultrafiltration rate.

countercurrent flow

Blood and dialysate flowing in opposite directions through the dialyzer to maximize the gradient and clearance.

AV fistula

An arteriovenous fistula — the surgeon joins the patient's own artery and vein; the preferred long-term access.

AV graft

A synthetic tube surgically placed to bridge an artery and a vein; the second-choice access.

central venous catheter

A catheter sitting in a large central vein; the last-resort access with the highest infection risk.

thrill

The continuous vibration felt over a patent AV fistula or graft, confirming blood flow through the access.

bruit

The whooshing sound heard with a stethoscope over a working AV fistula or graft.

cannulation

Inserting the dialysis needles into the vascular access (arterial and venous needles).

recirculation

Already-dialyzed blood re-entering the dialyzer instead of returning to the body, lowering clearance.

stenosis

Narrowing of the access vessel; signs include high venous pressures and a changed thrill/bruit.

steal syndrome

When the access diverts blood from the hand, causing a cool, pale, painful, numb hand distal to the access.

infiltration

Blood leaking into surrounding tissue when a needle perforates the vessel wall, causing swelling and pain.

dry weight

The lowest weight a patient tolerates without symptoms of fluid overload or depletion — the post-dialysis target.

interdialytic weight gain

Fluid weight gained between treatments; large gains require higher ultrafiltration and risk hypotension.

hypotension

A drop in blood pressure — the most common intradialytic complication, usually from too-rapid fluid removal.

disequilibrium syndrome

Headache, nausea, restlessness, or seizures from rapid urea and water shifts, common in first treatments.

hemolysis

Rupture of red blood cells in the circuit — cherry-red blood line — from chloramine, bad dialysate, or a kinked line.

air embolism

Air entering the bloodstream from the circuit — a true emergency the air/foam detector is designed to prevent.

heparin

The anticoagulant infused during treatment to keep the extracorporeal circuit from clotting.

extracorporeal circuit

The blood path outside the body — access, lines, pump, dialyzer, and monitors.

blood pump

The roller (peristaltic) pump that moves blood through the circuit at the prescribed blood flow rate (commonly 300–500 mL/min).

conductivity

A measure of dialysate electrolyte concentration that verifies the concentrates were mixed in the correct ratio.

reverse osmosis

The core water-purification step that rejects most dissolved ions, bacteria, and endotoxin.

chloramine

A water disinfectant that causes hemolysis if it reaches a patient; removed by the carbon tanks.

endotoxin

A pyrogen from gram-negative bacterial cell walls that causes fever/chills if present in water or dialysate.

dialyzer reprocessing

Cleaning, testing, and disinfecting a dialyzer so the SAME patient can reuse it (never shared).

URR

Urea reduction ratio — the percent drop in BUN across a treatment; the minimum adequacy target is about 65%.

Kt/V

A calculated dialysis-adequacy index; a common minimum target is about 1.2 per treatment.

hyperkalemia

A dangerously high blood potassium level that can cause cardiac arrhythmias — a key reason for dialysis.

ESRD

End-stage renal disease — irreversible kidney failure requiring dialysis or transplant.

glomerulus

The tuft of capillaries in each nephron that filters water and small solutes from the blood — the job dialysis replaces.

standard precautions

Treating every patient's blood and body fluids as potentially infectious through hand hygiene, gloves, and PPE.

PPE

Personal protective equipment — gloves, gown, mask, and eye/face protection.

QAPI

Quality Assessment and Performance Improvement — the facility process technicians help drive to improve care and safety.

CHT Study Guide FAQ

References

1. 1.Board of Nephrology Examiners Nursing and Technology (BONENT). “CHT Certification — Examination Content Outline & Candidate Information.” BONENT. ↑
2. 2.Centers for Medicare & Medicaid Services (CMS). “Conditions for Coverage for End-Stage Renal Disease Facilities (42 CFR §494).” CMS. ↑
3. 3.Centers for Disease Control and Prevention (CDC). “Dialysis Safety: Recommendations and Core Interventions to Prevent Infections.” CDC. ↑
4. 4.National Institutes of Health / National Library of Medicine. “StatPearls & MedlinePlus (hemodialysis, vascular access, complications, electrolytes).” NIH/NLM. ↑
5. 5.National Kidney Foundation. “KDOQI Clinical Practice Guidelines for Hemodialysis Adequacy & Vascular Access.” kidney.org. ↑
6. 6.Association for the Advancement of Medical Instrumentation (AAMI/ANSI). “Water Quality and Reuse Standards for Hemodialysis.” AAMI. ↑

Career Employer

Career Employer is the ultimate resource to help you get started working the job of your dreams. We cover topics from general career information, career searching, exam preparation with free study materials, career interviewing, and becoming successful in your career of choice.

Follow Us:

All Posts