- a weakness of the abdominal wall through which
the intestines or other intraabdominal contents
protrude. Dangerous to a diver if a loop of
air-containing intestine is trapped outside the
bottom time (ACT) - Total elapsed time in
minutes from leaving the surface until ascent
loss Anemia - Anemia brought on by hemorrhage.
An indication for the use of hyperbaric
Abbreviation for arterial gas embolism
air - a gas
mixture containing 21% oxygen, 78% nitrogen,
and 1% other gases (mainly argon); compressed
air is used for recreational scuba
compressor - a machine that compresses or
pressurizes air; for scuba purposes, air is
compressed from the atmospheric level (14.7
psi at sea level) to the capacity of the tank,
usually between 2500-3000 psi.
embolism - see arterial gas embolism
pressure - the force per unit area exerted by
the weight of air; at sea level the air
pressure is 14.7 psi. Air pressure decreases
with altitude. http://www.scuba-doc.com/gasesprbs.html
mood and attitude altering chemical that is a
substance often abused by individuals. It is
exceedingly dangerous underwater due to it's
ability to alter the decision making
a set of equations incorporated into diving
computers in order to compute nitrogen uptake
and elimination from changes in depth and
Vertigo - dizziness brought on by the
inequality of pressures in the inner ear. http://www.scuba-doc.com/vert.htm
Sickness - an illness brought on by the sudden
reduction in pressure of ascent to altitude.
air sac at the terminus of a bronchus where
oxygen and carbon dioxide transfer occurs.
any reduction in the oxygen carrying capacity
of the red blood cells. http://www.scuba-doc.com/hematology.htm
- Medications that reduce the clotting ability
of the blood. Particularly dangerous to divers
due to barotrauma of air-filled body
pressure - the surrounding pressure; on land,
comes from the weight of the atmosphere (see
air pressure); at depth, comes from the weight
of the water plus the weight of the
argon - an
inert gas that makes up less than one percent
- irregularities in the rhythm and rate of the
heart, particularly dangerous to divers due to
the underwater environment.
gas embolism - the condition characterized by
bubble(s) of air from a ruptured lung segment
under pressure; the bubbles enter the
pulmonary circulation and travel to the
arterial circulation, where they may cause a
stroke. (AGE or CAGE).
asthma - a
common condition manifested by narrowing of
air passages within the lungs (the bronchi);
one reason for the narrowing is excess mucous
in the airways.
atmosphere absolute; 1 ata is the atmospheric
pressure at sea level; is measured with a
- the blanket of air surrounding the earth,
from sea level to outer space. Also, a unit of
pressure; "one atmosphere" is pressure of the
atmosphere at sea level, i.e., 760 mm Hg. Two
atmospheres is twice this pressure, 1520 mm
Hg, etc. Abbreviated atm.
pressure - pressure of the atmosphere at a
given altitude or location.
- pain and discomfort caused by volume and
pressure changes in carous teeth.
pressure - same as atmospheric pressure.
- any disease or injury due to unequal
pressures between a space inside the body and
the ambient pressure, or between two spaces
within the body; examples include arterial gas
embolism, pneumomediastinum, and pneumothorax,
eye, middle ear and sinuses and the lung.
BC - see
bends - a
form of decompression sickness caused by
dissolved nitrogen leaving the tissues too
quickly on ascent; is manifested by pain,
usually in the limbs and joints; "the bends"
is sometimes used to signify any manifestation
of decompression sickness.
bleb - an
abnormal pocket of air in the lungs, usually
under the lining of a lung, that can rupture
with ascent and lead to barotrauma.
Calculation - http://www.scuba-doc.com/Nutrition.htm#Body
- variable definition; in square wave diving,
the time between descending below the surface
to the beginning of ascent. In multi-level
diving, the time between descending below the
surface and beginning the safety stop. (Other
definitions may apply depending on the
specific type of diving.)
Disease, Inflammatory - Inflammations of the
intestine, including Crohn's disease and
chronic ulcerative colitis. Some forms have
complications that are adverse to diving.
- at a fixed temperature and for a fixed mass
of gas, pressure times volume is a constant
diving - diving without life support
apparatus, while holding one's breath.
bubble - a
collection of air or gas surrounded by a
permeable membrane through which gases can
enter or exit.
similar to bleb; an abnormal pocket of air or
fluid; sometimes found in the lungs of
patients with emphysema.
tendency of object to float or sink when
placed in a liquid; objects that float are
positively buoyant, those that sink are
negatively buoyant and those that stay where
placed are neutrally buoyant. Buoyancy control
is a very important factor in diving safely.
compensator - an inflatable vest worn by the
diver that can be automatically or orally
inflated to help control buoyancy; abbreviated
Abbreviation for cerebral arterial gas
embolism (See arterial gas embolism)
dioxide - CO2; an odorless, tasteless gas that
is a byproduct of metabolism; is excreted by
the lungs in exhaled air. Important in the
control of respiration.
Retention - frequent cause of CO2 toxicity,
usually from skip breathing.
dioxide toxicity - problems resulting from
buildup of CO2 in the blood; they may range
from headache and shortness of breath, all the
way to sudden blackout.
monoxide - CO; odorless, tasteless, highly
poisonous gas given off by incomplete
combustion of hydrocarbon fuels.
monoxide toxicity - illness from inhaling
excess CO; problems may range from headache to
unconsciousness and death.
Charles' Law - at a constant
volume, the pressure of a gas varies directly
with absolute temperature.
At a constant pressure the volume
of a mass of gas is
proportional to the absolute
T x P = V
chokes - a
form of decompression sickness caused by
enough bubbles entering the lungs to interfere
with gas exchange; manifested by shortness of
breath and can be fatal.
Adverse Effects, Bone - dysbaric
osteonecrosis; bone damage done by nitrogen
bubbles in the bones.
Obstructive Pulmonary Disease (COPD ) -
terminal airway dilation and blockage from
long-term smoking, infection or other
chronically inhaled substances. Dangerous to
the diver due to possibility of 'burst lung'
and gas embolism.
Ulcerative Colitis (CUC) - inflammatory bowel
disease sometimes requiring ostomy.
Techniques - techniques to equalize the
Eustachian tubes while descending and
ascending during a dive.
circuit scuba - apparatus designed to allow
divers to re-breathe exhaled air after removal
of CO2 and addition of supplemental O2. In
contrast to "open circuit," closed circuit
scuba is noiseless and produces no bubbles.
Near-Drowning - drowning associated with cold
water and hypothermia.
and Valvular Heart Disease - Abnormal
passageways between the right (venous) and
left (arterial) sides of the heart from birth.
Heart valves that are deformed and don't open
and shut properly, thereby causing heart
Irritants and Toxins - Usually nematocysts and
toxins from sponges, corals and jellyfish.
to Diving - Listing of items that should cause
a person not to dive. http://www.scuba-doc.com/fitdiv.html
to HBO - Listing of items that would preclude
using HBO as a treatment method. http://www.scuba-doc.com/hbocont.htm
- a theoretical division of the body with an
arbitrarily assigned half time for nitrogen
uptake and elimination. In designing
decompression tables the body is divided into
a finite number of compartments for purposes
of making calculations, e.g., five, six or
see dive computer
Artery Disease - Abbreviation CAD.
Arteriosclerosis of the arteries supplying
blood to the heart. Blockage causes heart
failure and 'heart attacks'.
Disease - Inflammatory bowel disease
associated with fistulae and sometimes
Abbreviation for chronic ulcerative colitis
DCS - skin changes associated with
decompression sickness; includes cutis
marmorata, edema, maculopapular rash.
marmorata - see above. Usually a serious form
of DCS causing a mottled appearance of the
Law - the total pressure exerted by a mixture
of gases is equal to the sum of the pressures
that would be exerted by each of the gases if
it alone were present and occupied the total
- any change from one ambient pressure to a
lower ambient pressure; always results in a
reduction of gas pressures within the body.
dive - any dive where the diver is exposed to
a higher pressure than when the dive began;
the decompression occurs as the diver ascends.
schedule - Specific decompression procedure
for a given combination of depth and bottom
time, normally indicated as feet/minutes.
stop - on ascent from a dive, a specified time
spent at a specific depth, for purposes of
nitrogen off-gassing; when not mandatory it is
called a safety stop.
DCI - see
illness - DCI; a relatively new term to
encompass all bubble-related problems arising
from decompression, including both
decompression sickness and arterial gas
DCS - see
sickness - DCS; a general term for all
problems resulting from nitrogen leaving the
body when ambient pressure is lowered. Can be
divided into Type I (musculoskeletal and/or
skin manifestations only) or the more serious
Type II (neurologic, cardiac, and/or pulmonary
stop - the depth at which a diver must stop on
ascent for a specified period in order to
eliminate inert gas before continued ascent.
Thrombosis - clotted and blocked blood vessels
in the deep venous system of the legs and
- a condition where the water content of the
body is reduced; caused by immersion, alcohol,
medications, excessive loss of fluids from
vomiting and diarrhea or decreased intake of
depth - the
maximum depth in fsw attained during a dive
- inflammation of the skin from many sources.
Metabolic condition of decreased or absent
insulin production by the pancreas.
Diving - Special diving conditions and groups
that offer the diving experience to
people who have some kind of disability.
Disease Transmission Using Scuba Gear
Information about the scant risk of HIV
infection from buddy breathing and rental scuba
gear with links to sources about the possibility
of AIDS/HIV transmission.
Disease, Herniated - Extrusion of the cushion
disc between the vertebrae- usually laterally
placing pressure on the nerve roots of the
Quick Accident Response - Acclaimed guidelines
for the rapid assessment and management of
diving accidents of all types. http://www.scuba-doc.com/qkrsp.htm
Chemicals and medications that cause the
kidneys to excrete an increased quantity of
computer - a small computer, carried by the
diver, that constantly measures water pressure
(and hence depth), and time; based on a
pre-programmed algorithm, the computer
calculates tissue nitrogen uptake and
elimination in several theoretical
compartments and provides a continuous readout
of the dive profile, including: depth, elapsed
time of dive, duration at current depth before
decompression becomes mandatory; and a warning
if the rate of ascent is too fast.
- a printed collection of dive times for
specific depths, by which the diver can avoid
contracting DCS. Most tables are based on
Haldanian theory for nitrogen uptake and
dry suit -
a water-tight garment that keeps the diver's
body warm by providing insulation with a layer
of gas, such as air; for diving in waters that
are too cold for comfortable wet suit
protection, usually below 65°F.
Osteonecrosis - Permanent damage done to the
bones and joints by long-term diving.
enriched air nitrogen; nitrox.
- without teeth; also usually with dentures.
Arterial Gas - see arterial gas embolism
related to hormonal excretion of regulatory
ENT - Ear,
Nose and Throat diseases and conditions.
Mixture of nitrous oxide and oxygen (50-50).
Dangerous to administer to divers.
condition of the brain associated with
seizures, inimical to diving.
tube - a short, muco-cartilaginous tube
connecting the back of the nose to the middle
ear. The anatomy of this tube is such that it
tends to close naturally when ambient pressure
is higher than middle ear pressure (as on
descent in a dive), and tends to open
naturally when ambient pressure is lower than
middle ear pressure (on ascent).
Otitis - otitis externa. Infection of
the ear canal.
regulator - regulator attached to the scuba
tank that lowers the tank pressure to ambient
pressure + a pre-determined pressure (e.g.,
ambient + 140 psi).
gas in the gi tract produced by the products
of digestion or swallowed air, as when
Ovale, Patent - Opening in the heart between
the right and left atria that remains open in
about 30 % of people, allowing passage of
bubbles into the arterial circulation and
symptoms of arterial gas embolism.
- variably defined; in some usage, diving
without any scuba or other equipment and
synonymous with breath-hold diving; in other
usage, diving with-out any attachment to the
surface, and therefore includes scuba diving.
fsw - feet
of sea water; used to indicate either an
actual depth, or just a pressure equal to that
depth (e.g., in a hyperbaric chamber).
Overactive - the inability to retain an object
in the mouth without gagging or retching.
embolism - see arterial gas embolism
gas laws -
laws that predict how gases will behave with
changes in pressure, temperature and volume.
- pertaining to the digestive tract.
pressure - pressure exclusive of atmospheric
pressure; when diving, gauge pressure is due
solely to the water pressure.
pertaining to the passage of traits from one
individual to another through genes and
abnormal condition of increased intra-ocular
pressure, leading to blindness if uncorrected.
half time -
half the time it takes for a dissolved gas in
a tissue (such as nitrogen) to equilibrate to
a new pressure, or to reach full saturation at
a new pressure. Theoretical tissue half times
are used in designing dive tables and
algorithms for dive computers.http://www.scuba-doc.com/gasesprbs.html
related to Haldane's theory that nitrogen is
taken up and given off in exponential fashion
during a dive, and that there is some safe
ratio of pressure change for ascent
Marine Life - living creatures in the marine
environment that are dangerous or harmful to
Chambers - chambers that lower (or raise) the
pressures surrounding an individual, usually
using periods of 100% oxygen for purposes of
treating diving and other conditions.
Loss - a hazard of diving, usually associated
with rupture of round window or inner ear DCS.
reflux of acid gastric juice into the lower
esophagus. Also called GERD.
mixture of helium and oxygen, used for very
deep diving. http://www.scuba-doc.com/gasesprbs.html
second lightest gas; does not cause problems
of narcosis seen with nitrogen, and is
therefore used for very deep diving.
- the amount of any given gas that will
dissolve in a liquid at a given temperature is
a function of the partial pressure of the gas
in contact with the liquid and the solubility
coefficient of the gas in the liquid.
- the study of the blood.
hernia - a
weakness of the abdominal wall through which
the intestines or other intraabdominal
contents protrude. Dangerous to a diver if a
loop of air-containing intestine is trapped
outside the abdomen.http://www.scuba-doc.com/giprbs.html
Disc Disease - see disc disease.
see abdominal hernias
pressure nervous syndrome - convulsions or
seizure-like activity arising from high gas
pressure at depth, especially with helium.
Abbreviation is HPNS.
hookah - a
surface-supplied compressed air apparatus, for
use in shallow diving in calm waters. The air
is delivered to one or more divers through a
an inert gas, and lightest of all the
elements; has been used in experimental diving
chamber - air-tight chamber that can simulate
the ambient pressure at altitude or at depth;
is used for treating decompression illness.
- a higher than normal PCO2 level in the
blood. Also hypercarbia. http://www.scuba-doc.com/gasesprbs.html
- condition where the blood pressure (gauge)
is above 140/90. http://www.scuba-doc.com/hrtprb.html
- a body temperature warmer than normal; less
common in diving than hypothermia, but can
occur from overheating in a wet suit.
- condition where the thyroid gland produces
too much hormone. http://www.scuba-doc.com/endmet.html
- condition where an individual breathes too
rapidly and has a lowered CO2, lowered Ca++
with the production of tetany; usually due to
- a body temperature colder than normal
(37°C/98.6°F); severe problems start
to manifest when body temperature reaches
about 35°C (95°F).http://www.scuba-doc.com/hypoth.htm
- under breathing to the extent that the blood
carbon dioxide level is elevated; may be
manifested by carbon dioxide narcosis.
lower than normal PO2 level in the blood;
insufficient oxygen in the blood.
same as hypoxemia; terms are often used
Latent - see shallow water blackout
Hypothermia - lowering of body temperature by
full body immersion in cold water. See
HIV - infection with the human immune virus.
Not necessarily a contra-indication to diving.http://www.scuba-doc.com/aaids.htm
Marine Wound - infection wit marine organisms
that are particularly virulent and resistant
to usual antibiotics. http://www.scuba-doc.com/aaids.htm
Bowel Disease - inflammations of the
intestines, including CUC and Crohn's disease.
Inner Ear -
that portion of the ear in the petrous bone
that has to do with hearing organs and
Gas - see flatus.
hypoxia - a sudden unconsciousness, from
hypoxia, that occurs among some breath hold
divers. Often occurs near the surface after a
deeper dive. Same as "shallow water blackout."
Lice, sea -
description of the condition caused by the
nematocysts of the thimble jellyfish.
sign - circumscribed pallor of the tongue
associated with Arterial Gas Embolism.http://www.scuba-doc.com/ageprbs.html
- a dive boat with sleeping and eating
accommodations. Commercial liveaboards are
usually between 50 and 130 feet long, and can
carry anywhere from 10 to 30+ divers for a
week or more.
Mal de mer
- motion sickness or sea sickness.
Syndrome - Familial condition produced by an
absent protein that causes, among other
things, aortic aneurysms and pulmonary cysts.
Associated Infections - infectious organisms
living in sea water that are particularly
virulent to immunosuppressed individuals.
Hazards - Ocean life that offer hazards to the
Prescription Dive - masks especially produced
with a prescription for the individual diver.http://www.scuba-doc.com/diveye.htm
- air-containing space of the ear bordered on
one side by the tympanic membrane, which is
exposed to any change in ambient pressure. Air
pressure in the middle ear space can only be
equalized through the eustachian tube, which
connects the middle ear to the back of the
Barotrauma - damage done to the middle ear due
to inability to equalize the pressure
differentials as a diver descends and ascends.
recurring headaches that are triggered
by certain exogenous factors such as stress,
dietary indiscretions, allergens.
Valve Prolapse - an incompetent, floppy valve
in the heart between the left atrium and
mixed gas -
variously defined; basically, any non-air
mixture (e.g., nitrox), although some authors
use the term only for mixes that contain a gas
in addition to (or in place of) nitrogen
Sclerosis - Demyelinating neurological illness
causing symptoms similar to DCS.
Congestion - swollen, blood-filled linings of
the nose and sinuses, often due to allergies
National Association of Underwater Instructors
Drowning, Cold Water Immersion - see
inert gas that makes up 78% of air. Nitrogen
is inert in that it does not enter into any
chemical reaction in the body, but it can
cause problems under pressure (see nitrogen
narcosis, decompression sickness).
depressed mental state, anywhere from
confusion or drowsiness to coma.
narcosis - depressed mental state from high
nitrogen pressure; usually does not begin to
manifest on compressed air until below 80 fsw.
any mixture of nitrogen and oxygen that
contains less than the 78% nitrogen as found
in ordinary air. http://www.scuba-doc.com/gasesprbs.html
National Oceanic and Atmospheric Association.
Problems - problems of the brain and spinal
cord caused by diving; neurologic difficulties
adversely impacting the diver (epilepsy)
Oxygen enriched air; nitrox.
circuit scuba - apparatus used in recreational
diving; exhaled air is expelled into the water
as bubbles; no part is rebreathed by the
inflammation or infection of any part of the
ear; otitis media involves the middle ear,
otitis externa the outer ear (ear canal).
externa - inflammation and infection of the
external auditory canal - usually due to
fungus and decreased acidity of the canal.
- see dysbaric osteonecrosis
Gag reflex - see gag reflex
O2; gas vital for all life on this planet;
makes up 21% of air by volume. http://www.scuba-doc.com/gasesprbs.html
therapy - administration of any gas, for
medical purpose, that contains more than 21%
toxicity - damage or injury from inhaling too
much oxygen; can arise from either too high an
oxygen concentration or oxygen pressure. The
first manifestation of oxygen toxicity while
diving can be seizures.
window - difference between total gas
pressures in arterial and venous blood; exists
because oxygen is partly metabolized by the
tissues, so venous oxygen pressure is lower
than arterial oxygen pressure. http://www.scuba-doc.com/gasesprbs.html
- molecule of combination between oxygen and
hemoglobin responsible for the transfer of
oxygen from the lungs to the tissues.
- electronic device that sends signals to the
heart causing a rhythm change. http://www.scuba-doc.com/hrtprb.html
Professional Association of Diving Instructors
pressure - pressure exerted by a single
component of a gas within a gas mixture, or
dissolved in a liquid. http://www.scuba-doc.com/gasesprbs.html
pressure, carbon dioxide - PCO2; pressure
exerted by carbon dioxide in any mixture of
gases, or dissolved in a liquid.
pressure, nitrogen - PN2; pressure exerted by
nitrogen component in any mixture of gases, or
dissolved in a liquid. http://www.scuba-doc.com/gasesprbs.html
pressure, oxygen - PO2; pressure exerted by
oxygen in any mixture of gases, or dissolved
in a liquid.http://www.scuba-doc.com/gasesprbs.html
foramen ovale - see foramen ovale
- abnormal collection of air in the middle
part of the chest, between the two lungs
(mediastinum); often a consequence of
- abnormal collection of air outside the
lining of the lung, between the lung and the
chest wall; often a consequence of barotrauma.
Water, Diving - special equipment and
procedures for diving in polluted waters.
vera - condition of abnormal increase in
production of red blood cells. http://www.scuba-doc.com/hematology.htm
Dive masks - dive masks produced especially
for divers needing refractive correction.http://www.scuba-doc.com/diveye.htm
any force exerted over an area; see
atmospheric pr., ambient pr. http://www.scuba-doc.com/gasesprbs.html
pounds per square inch; a common measurement
of air pressure. http://www.scuba-doc.com/gasesprbs.html
Barotrauma - rupture of the lung surface from
increased pressure of ascent from depth.
Usually due to closed glottis, pulmonary blebs
or terminal airway disease. Causes arterial
gas embolism, pneumothorax, pneumomediastinum.
Edema of Diving - fluid accumulation in the
lungs secondary to immersion and pressure
Decompression Sickness (Chokes) - see chokes
Frequently Asked Questions
Syndrome, and is identified by specific genes
that cause the abnormality. [The Q-T
interval is ... Drugs Can Prolong the Q-T
interval The combination ... and a prolonged Q-T
Accident Response Page, Divemasters
Aids and butterfly bandages Q-TipsTongue
Disposable cups Razor blades, single edged
Shaving cream Tweezers or forceps Needle nosed
pliers with wire cutters (to remove
mismatching in Hypothermia
and Near Drowning
. As much as 75% of blood flow may circulate
through hypoventilated lungs. In salt water
near drowning, surfactant washout occurs, and
rapid exudation of protein-
scuba diving - diving to prescribed limits,
including a depth no greater than 130 fsw,
using only compressed air, and never requiring
a decompression stop; abbreviated RSD.
Correction -lens configuration needed to
correct a defect in a divers vision.
in scuba, any device which changes air
pressure from one level to a lower level. See
first and second stage regulator.
dive - any dive done within a certain time
frame after a previous dive; variable
definition exists as to what time frame
constitutes "repetitive." With some tables any
dive within 12 hours of a previous dive is
considered repetitive; when using a computer,
any dive whose profile is affected by a
previous dive is considered repetitive.
nitrogen - nitrogen that remains dissolved in
a diver's tissues after surfacing from a dive.http://www.scuba-doc.com/gasesprbs.html
nitrogen time - the time it would take to
off-gas any extra nitrogen remaining after a
dive; in dive tables, RNT is designated by a
letter A through Z. Residual nitrogen time is
always taken into consideration in determining
the safe duration for any repetitive dive.
squeeze - pain or discomfort in enclosed space
(e.g., sinuses, middle ear, inside face mask)
on ascent from a dive.
- on ascent from a dive, a specified time
spent at a specific depth, for purposes of
nitrogen off-gassing; by definition it is not
mandatory for safe ascent from the dive.
Compare with decompression stop.
- the degree to which a gas is dissolved in
the blood or tissues; full saturation occurs
when the pressure of gas dissolved in the
blood or tissues is the same as the ambient
(surrounding) pressure of that gas.
diving - diving performed after the body is
fully saturated with nitrogen; to become fully
saturated the diver must stay under water for
a much longer period than is allowed in
recreational scuba diving tables.
self-contained underwater breathing apparatus.
sea level -
the level of the world's oceans; all oceans
are at sea level.
Sea Lice or
Seabather's Eruption - dermatitis secondary to
nematocysts of the thimble jellyfish.http://www.scuba-doc.com/mrnlfhz.html
- motion sickness or mal de mer
stage regulator - the regulator that follows,
in line, the first stage regulator, and
delivers compressed air to the diver.
water blackout - a sudden unconsciousness,
from hypoxia, that occurs among some breath
hold divers. Often occurs near the surface
after a deeper dive, hence "shallow water."
Same as 'latent hypoxia'. http://www.scuba-doc.com/gasesprbs.html
Illness - inherited illness in which deformed
red blood cells cause blood vessel blockage.
Low oxygen precipitates a crisis.
- Any dive conducted at least 12 hours after a
air spaces within the skull that are in
contact with ambient pressure through openings
into the back of the nasal passages.
inflammation or infection of the sinuses in
the head. http://www.scuba-doc.com/entprobs.html
Syndrome - An arthritic condition associated
with drying out and loss of salivary gland
activity, tear duct activity and adverse to
- another term for breath-hold diving; diving
without the use of scuba equipment.
- this simply means holding the breath after
breathing in and/or holding the breath for a
variable period of time after breathing out.
This is done subconsciously or on purpose in
order to "conserve air" - either to stop using
too much air or to try to prolong a dive. It
is dangerous for several reasons. It causes a
subtle buildup of CO2 with all of the
attendant risks [see our web pages about this
]. In addition, it imposes the risk of
pulmonary barotrauma from ascending with the
glottis closed, even a few feet. There are
several web sites that discuss breathing
control in terms of learning buoyancy control
- but managing breathing for this is entirely
different and does not entail 'holding the
breath' but increasing and decreasing volumes.
bifida - congenital anomaly of the spinal
cord; often associated with paraplegia, bowel
and bladder dysfunction http://www.scuba-doc.com/nbjprb.htm
abnormal absorption of the GI tract;
associated with cerebral calcifications and
seizures. Also called coeliac disease.
pain or discomfort in an enclosed space
(sinuses, middle ears, inside a face mask)
caused by shrinkage of that space; occurs on
descent. See reverse squeeze.http://www.scuba-doc.com/entprobs.html
pathological damage to the skin from the
ultraviolet rays of the sun. http://www.scuba-doc.com/derm.html
interval - length of time on the surface,
usually out of the water, between two
air diving - diving with the air continuously
supplied by a compressor on the surface; can
be used for both sport and professional
- an unstable situation where the pressure of
a gas dissolved in the blood or tissues is
higher than the ambient pressure of that gas.
Supersaturation is always present to some
degree with every decompression.
Itch - pruritic condition from diving in
cercaria infested waters. http://www.scuba-doc.com/derm.html
Native word used to describe the decompression
condition that develops with frequent, deep
breath-hold dives with short surface intervals.
Classification - a method to classify the
degree of damage done to the tympanic
membranes and middle ear from barotrauma.
Named after R W Teed who wrote in many
otological journals describing the
aetiology, clinical findings and pathology of
middle ear barotrauma. (Thanks to Carl Edmonds
for this information!)http://www.scuba-doc.com/entprobs.html
- intersection between two layers of water of
that are of decidedly different temperatures;
usually the colder layer is deeper. A diver
can easily feel a thermocline.
(Transient ischemic attacks) neurological
condition of decreased consciousness and
paralysis due to small emboli going to the
cerebral circulation. Also called
'Little Strokes'. http://www.scuba-doc.com/nbjprb.htm
ringing sound heard by some divers after
barotrauma to the inner ear. Sometimes caused
by perilymph fistula and occasionally needs
tissue - a
part of the body characterized by specific
characteristics, such as muscle, bone, or
cartilage. The term is also used to refer to
any part of the body with a specific half time
for loading and unloading nitrogen; in this
latter context a tissue may be contiguous or
non-contiguous, or even a theoretical
Syndrome - Jaw and ear pain from clamping the
teeth around a regulator mouthpiece.
O2 - the condition caused by oxygen at depth
(increased pressure); usually ends in
convulsions, and, drowning if under water.
Pulmonary Oxygen - Condition of the lungs
caused by oxygen given at increased pressure.http://www.scuba-doc.com/pulprbs.html
mixture of helium, nitrogen and oxygen, used
for very deep diving.
membrane - the thin ear drum between the outer
ear and the middle ear, visible to the
examiner with an otoscope. http://www.scuba-doc.com/entprobs.html
Minor explosions have caused blast injury &
death during underwater electric cutting
& ... same distance an underwater
blast is more ... waves from an underwater
explosion combine with
Thrombosis, Anticoagulation - See Deep vein
Polycythemia - Pathological condition whereby
the bone marrow produces too many cells.http://www.scuba-doc.com/hematology.htm
Dizzy, unbalanced feeling often caused by
diving problems with the inner ear.
Diving in Polluted - http://www.scuba-doc.com/polwater.html
Problems With Moving - http://www.scuba-doc.com/divcurr.htm
Hypothermia and Cold Water Near Drowning - http://www.scuba-doc.com/hypoth.htm
pressure - force per unit area exerted by the
weight of water; each 33 feet of sea water
exerts a pressure equivalent to one
atmosphere, or 14.7 psi.
wet suit -
any suit that provides thermal protection in
or under water by trapping a layer of water
between the diver's skin and the suit; see dry
X or Eosinophilic granuloma,
X as a cause of pulmonary barotrauma in
scuba ... in 30%, and progression in 30%.
Scuba diving is contraindicated. X-ray:
CXR: On CXR there is usually diffuse