The following recommendations
and guidelines is relative conservative and it may only apply to
sport divers. Any unclear information and further advice should
be obtained from your diving physician.
Contents of FAQ in Diving
- Coronary Artery Disease (CAD)
Ideally, one would like to
establish a baseline and periodic cardiovascular
screening program for all divers, which would
provide laboratory determination of serum lipids,
risk factor analysis, resting and exercise
electrocardiography and exercise scintigraphy.
Scuba diving candidates over the age of 40, and
poorly conditioned diving candidates under 40
should have an exercise electrocardiogram for
assessment. To participate in scuba diving,
approximately 13 METS should be achieved in
exercise electrocardiogram. In the presence of an
abnormal exercise ECG, such a candidate may be
tested with exercise ECG with scintigraphy and,
if possible, coronary angiography.
Those divers with symptoms of angina pectoris,
history or finding of myocardial infarction
arrhythmias due to CAD represent
contraindications to diving.
In rare exceptional individuals who undergo
successful coronary angioplasty and coronary re-vascularization
and those who recover from discrete, non-complicated
myocardial infarctions, who have completed
rehabilitation programs with life-style and risk
factor modification can be evaluated individually
for diving. Return to diving would be only after
the usual non-invasive testing procedures by
cardiologist to rule out myocardial ischemia.
Drugs which alter cardiovascular response to
exercise is not acceptable and risk of drowning
and risk to their diving buddies must be advised.
Regular check-up by cardiologist with experience
in diving medicine on an annual basis and
maintain a high level of physical conditioning to
avoid excess cardiovascular stress in diving.
Hypertension controlled by
weight loss, salt restrictions and exercise,
diving can be safe. Further, well controlled by
these measures plus diuretics can also continue
to dive. Due to the potential need to increase
the cardiac output in response to heavy exercise
in a diving emergency requires that those taking
beta blocking agents or other drugs which produce
significant blockade of the nervous system should
demonstrate adequate performance on an exercise
test to 13 METS. All hypertensive patient with
left ventricular hypertrophy, left ventricular
dilation or left ventricular dysfunction should
not continue diving , even if blood pressure is
controlled. Current recommendation on chooses of
anti-hypertensive medication for divers are from
ACE inhibitor and Calcium channel blockers rather
then from beta-blocking drugs.
For mitral regurgitation,
if no evidence of left ventricular function and
asymptomatic with minimal left ventricular
dilation on ECG and echocardiogram that diving
can be continues.
Aortic insufficiency with hemodynamically
insignificant changes and asymptomatic can be
qualify for diving. However ECG and
echocardiogram must show no left ventricular
hypertrophy, minimal left ventricular dilation,
and no left ventricular dysfunction.
Any other degree of aortic stenosis or mitral
stenosis is considered disqualifying for diving
since they impede forward flow during exercise
and pulmonary edema and/or syncope will be the
result. Diver with asymptomatic Mitral valve
prolapse are fit for diving except medication,
chest pain, palpitation, arrhythmias, syncope,
dyspnea complicating the disease.
- Congenital Heart Disease
ANY DEFECT WHICH ALLOWS A
COMMUNICATION BETWEEN THE RIGHT AND LEFT
CIRCULATIONS AT THE LEVEL OF THE HEART OR GREAT
VESSELS SHOULD CAUSE DISQUALIFICATION.
Divers who have had successful repair of non-cyanotic
lesions, such as atrial septal defects, patent
ductus arteriosus and ventricular septal defect,
may be cleared for diving after evaluation by a
cardiologist and by a chest physician.
In general, patients who
require permanent pacemakers are disqualified for
diving due to their underlying cardiac disease.
The only possible exception to this may be the
young individual with congenital third degree A-V
block who need full evaluation by their
cardiologist to evaluate their functional status
and the pacemaker's ability to perform
physiologically. Besides, pacemakers have been
tested in hyperbaric chambers and showed no
change in performance or structural integrity
under increased barometric pressure, such tests
would be required before considering diving with
pacemakers. Those healthy divers with
supraventricular arrhythmias treated with
catheter AV node destruction on implanted
pacemakers may also be suitable for diving.
- Bronchial Asthma
All exercise-induced asthma
is considered an absolute disqualification for
Any patient with currently active bronchial
asthma should be advised not to dive. Any patient
with a history of childhood asthma, symptoms
suggestive of asthma within the past year,
suspicion of exercise or cold air conduced asthma
should be referred to a pulmonary medicine
specialist for valuation. Current data shown that
an asthmatic diver who demonstrated to be have
normal resting and post-exercise lung function
test is not at risk when diving. However,
medication for acute asthma control within 48hours
before diving is not acceptable.
ONE CAUTIOUS REMINDER MUST
BE REPEATED: THE GREATEST VOLUME CHANGES IN THE
LUNGS OF ANY DIVER WITH AIR TRAPPING OCCUR AT
SHALLOW DEPTHS. NEVER CLEAR A PERSON FOR-SHALLOW
DIVING ONLY THE SHALLOWEST FOUR FEET, EVEN IN A
SWIMMING POOL IS THE MOST DANGEROUS DEPTH FOR
COMPRESSED GAS DIVING FOR A PATIENT WITH ACTIVE
Current recommendation is that no diving for those with insulin
dependent diabetes mellitus (IDDM) or with non-insulin dependent
diabetes mellitus (NIDDM) if there is a history of hypoglycemic
episodes. A diabetic diver without any complication is qualified
to dive even oral hypoglycemic medication is necessary for
contraindications to diving: Intraocular gas,
Intraocular hollow implant, and inadequate vision for
Special considerations regarding common ocular
- Glaucoma and Ocular
The existence of glaucoma
or ocular hypertension can practice diving as
long as adequate visual acuity and visual fields
exist. A candidate using Timoptic should be
cleared by a cardiologist for diving (the use of
Timoptic eye drops can affect the heart rate and
response to stress).
Diving can continue after a successful Laser
trabeculoplasty for treatment of glaucoma.
Duration of convalescent times after eye surgery
should be consulted with diver's ophthalmologist.
- Retinal detachment
Repaired or laser
photocoagulation in retinal detachment patient
can continue diving provided a regular ocular
examination by ophthalmologist maintained.
Patients with cataracts who
still have adequate vision and Aphakia with
contact lens correction for visual acuity can
- Visual Acuity corrections
Divers who need underwater
refractive correction are recommended to try soft
contact lenses, corrective lenses boned onto face
mask surface or prescription-ground face mask
avoid bubble formation in hard contact lenses.
Neurology in diving
The main considerations on return to diving
after head trauma are on its residual neurologic deficit which
would interfere with performance and the risk of post-traumatic
seizures. History of intracranial haemorrhage, brain contusion,
seizures that occur soon after the injury, or prolonged
unconsciousness or amnesia all raise the risk of post-traumatic
seizure disorders. Advice from neurologist or neurosurgeon should
Migraine sufferers who have shown any of the
following unpredictable sudden onset of an aura with impairment,
notably vision, loss of sensation or function of a hand, cause
produce severe mood alterations or, in the case of basilar artery
migraine, causes vertigo, diplopia or clouding of consciousness
or the severe headache accompanied by nausea, vomiting and
photophobia may suddenly impair a diver's ability to function
safely underwater and should be disqualified for diving.
Exception will be allowed for those well controlled with
Major or minor seizure disorders is
absolutely disqualifying for diving, regardless of control by
anticonvulsant medication. The attack may be preceded by a
warning or aura which is usually momentary and may be a motor,
sensory or emotional change, indicating the part of the brain
where the discharges start. The typical periodic breathholding
during the tonic and clonic phases of a major seizure make rescue,
bringing the diver to the surface, an especial risk for pulmonary
overpressure accident with resulting pneumothorax or arterial gas
Febrile convulsion occur in childhood which do not have any
abnormal neurological changes, long duration of seizure or
positive family history of non-febrile seizures are safe to dive.
A history of episodes of unconsciousness early in life should
evoke evaluation. The neurological evaluation at the time of the
episodes may have included EEG, but normal EEG would not overrule
a good clinical impression that the attack was due to epilepsy. A
history of epileptiform seizures in childhood is disqualifying
for diving unless there is good evidence they were simple febrile
Incidence of DCS occurs relative higher in
injured parts of the body and injured spine therefore it should
be mention to divers. A history of spinal cord trauma with
neurologic deficit should be cause for disqualification, with or
without residual deficit. A history of Guillain-Barre Syndrome,
Brown-Sequard Syndrome, degenerative joint disease as seen with
spinal stenosis and cervical disc disease with peripheral sign
are all considered disqualifying. Rare exceptions can be reviewed
case by case by diver's
History of Cerebrovascular Accident
Diver with a history of cerebrovascular
accident should be disqualification for diving. Even though
function has apparently been restored, the likelihood of loss of
neural reserve and possible local CNS hypoperfusion make serious
CNS decompression sickness more likely. While a history of
transient ischemic attack is also disqualifying.
Those divers with a trigger zone in the
face mask contact area could suffer attacks during diving or
donning diving gear. Trigeminal neuralgia attack with severe pain
can induce a panic attack which is not acceptable underwater and
therefore not fit for diving.
Diver with peripheral neuropathy needs
individual evaluation regarding underlying disorders and
functional disability, which could interfere with diving
activities. In general, disqualification must be advised because
of inability to differentiate neuropathy from decompression
sickness in diving. Known sensory loss, which may result in
severe, undetectable injury from diving, is also disqualified.
system in diving
Esophageal diverticula, significant
free gastroesophageal reflux, achalasia, sliding hiatal
hernia are not fit for diving.
Gastric outlet obstruction, severe post-gastrectomy
dumping syndrome is disqualifying for diving.
Small intestine obstruction, continent
ileostomy and exterocutaneous fistulae are disqualify for
Significant fatty liver is liable to
have inert gas excess and rupture of fat cells resulted
in unfit for diving.
information provided by Dr Ronson C.T. LI