Physiology of Breath-Hold Diving: Research Summary

By Rubicon Foundation editorial team

5 min read · 22 October 2026

Physiology of Breath-hold Diving, edited by Lundgren CEG (ed.) and Ferrigno M (ed.), is a 1985 workshop proceedings volume addressing how the human body responds to diving without breathing equipment. The subject matters because breath-hold diving combines apnea, immersion and changing pressure, creating distinctive physiological demands relevant to divers, clinicians and diving research.

What makes breath-hold diving a distinct physiological problem?

During a breath-hold dive, a person descends and returns to the surface without breathing underwater. The body must function while oxygen is consumed and carbon dioxide accumulates, while immersion and pressure alter the conditions affecting the lungs and circulation.

These demands distinguish apnea diving from scuba diving, where the diver breathes from a supply, and from ordinary breath-holding on land. The duration and depth of a dive, exertion, water temperature and individual physiology can all shape the body’s response.

How do apnea, immersion and pressure interact?

Apnea means temporarily stopping ventilation. As the breath-hold continues, oxygen availability falls and carbon dioxide rises; the resulting sensations and physiological responses influence a diver’s capacity to continue safely. These changes matter especially when a diver is exerting effort or attempting to extend a breath-hold.

Immersion shifts blood centrally from the limbs, while increasing water pressure compresses gas-containing spaces as depth increases. These effects interact with the mechanics of breathing and circulation. Understanding them helps explain why breath-hold diving cannot be assessed simply as an exercise in holding one’s breath.

Apnea and gas exchange: oxygen depletion and carbon-dioxide accumulation during a breath-hold.
Immersion and circulation: cardiovascular responses to being submerged.
Pressure and lung mechanics: changes affecting gas-containing spaces during descent and ascent.
Exertion and environment: factors that can alter physiological demand and risk.

Why does this subject matter for dive medicine?

Breath-hold diving can involve loss of consciousness, particularly when declining oxygen impairs brain function. A diver may not receive a reliable warning that consciousness is about to be lost, so prevention and close attention to safe diving practices are central concerns.

For diving physicians and hyperbaric clinicians, the subject connects respiratory and cardiovascular physiology with the assessment of underwater incidents. Breath-hold diving also raises questions about pressure-related effects and how symptoms arising during or after a dive should be understood. Individual health concerns require assessment by a diving-medicine physician.

Where do workshop proceedings fit in diving research?

A workshop proceedings volume brings together a scientific subject under discussion at a particular point in the development of a field. Here, the subject is breath-hold diving physiology, situated within the broader study of human performance and health under water.

Research in this area examines how physiological responses vary with apnea, immersion, depth and activity, and how those responses relate to performance and safety. Its concepts complement research on compressed-gas diving and hyperbaric exposure, while addressing the distinct conditions created by diving without a breathing supply.

Frequently asked questions

What is breath-hold diving?

It is diving underwater while holding the breath rather than breathing from underwater equipment. It combines apnea with immersion and exposure to increasing pressure during descent.

Why can a breath-hold dive become dangerous?

Oxygen falls during apnea, and severe oxygen deprivation can impair brain function and lead to loss of consciousness. Immersion, exertion and pressure add further physiological demands.

Who may find this subject useful?

Divers, diving physicians, hyperbaric clinicians and scientific divers may find the physiology relevant to understanding underwater responses and safety. Personal medical questions should be discussed with a diving-medicine physician.

Citation details

Title: Physiology of Breath-hold Diving. 31st Undersea and Hyperbaric Medical Society Workshop
Authors: Lundgren CEG (ed.); Ferrigno M (ed.)
Year: 1985
Published in: Undersea and Hyperbaric Medical Society
Record type: Workshop proceedings
Repository record: Rubicon Research Repository, handle 123456789/7992

This page is an original summary written by the Rubicon editors from the publication’s bibliographic record. It does not reproduce the paper, its abstract or its data; consult the publication itself for its methods and findings.