CHS Study Guide 2026

Everything you need to pass the CHS exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.

📋 CHS Exam Format at a Glance

100
Questions
120 min
Time Limit
70%
Passing Score

📚 CHS Topics to Study (21)

✍️ Sample CHS Questions & Answers

1. In CHS practice, what constitutes a conflict of interest?
When personal interests could compromise professional judgment

A conflict of interest occurs when personal, financial, or other interests could potentially influence professional judgment and decisions.

2. What is the first step in CHS risk assessment?
Identifying potential hazards and threats

Risk assessment begins with systematic identification of all potential hazards, forming the foundation for all subsequent analysis.

3. A diver reports progressive tingling in both legs after surfacing from a deep dive. This bilateral lower extremity paresthesia most likely indicates what type of DCS?
Spinal cord DCS (Type II), requiring urgent HBOT

Bilateral paresthesias of the lower extremities strongly suggest spinal cord bubble formation affecting the thoracic or lumbar cord, classifying this as Type II (neurological) DCS.

4. What is the maximum delay between DCS symptom onset and first HBOT treatment still considered likely to provide neurological benefit?
There is no absolute cutoff; treat as soon as possible even if delayed by hours or days

While earlier treatment is always better, HBOT can still provide benefit in DCS even when delayed by 24 hours or more, particularly for neurological symptoms, and should never be withheld solely due to delay.

5. Which condition is treated with US Navy Treatment Table 5 rather than Table 6?
Mild Type I DCS (pain only) that resolves completely with initial oxygen breathing at 60 fsw

USN TT5 is appropriate for mild Type I DCS (musculoskeletal pain, skin symptoms) that fully resolves during the initial oxygen-breathing period at 60 fsw, indicating a favorable response.

6. What is evidence-based practice in CHS Infection Control & Prevention?
Integrating research evidence with expertise and client needs

Evidence-based practice combines research, expertise, and client preferences for optimal outcomes.

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Your CHS Study Path
1. Learn with Flashcards → 2. Drill Practice Tests → 3. Take the Full Exam Simulation