What factors determine a diver's medical fitness to dive?

• A. Dietary choices.
• B. Age.
• C. Cardiovascular health, respiratory function, recent illnesses, medications, and fit-to-dive assessments.
• D. Hair color.

Answer: (C)

Medical fitness to dive hinges on how well the body tolerates the stresses of immersion, pressure changes, and gas exchange. The most important factors are cardiovascular health, because the heart must circulate blood efficiently under water and during ascent; respiratory function, since lungs and airways must manage breathing and gas exchange in a compressed environment; and the impact of recent illnesses and medications, which can temporarily or permanently affect safety or interact with diving physiology. A fit-to-dive assessment brings all of this together through medical history, a physical examination, and any required tests to determine if it’s safe to dive now and what precautions or restrictions might be needed.

Dietary choices affect general health but don’t directly determine immediate diving safety in the way cardiovascular and respiratory status do. Age can influence risk, but it by itself doesn’t decide fitness without considering specific health conditions. Hair color has no bearing on dive safety.