Disorder	Clinical features	Dive profile	Treatment
Middle ear barotrauma of descent	Acute pain, vertigo, hearing loss, rupture or hemorrhage of tympanic membrane	During descent usually, possible during ascent	Improved equalization techniques, oral and nasal decongestants; with otorrhea use antibiotics
Facial baroparesis	Ipsilateral facial paralysis, resolves within hours	During ascent	No treatment
Inner ear barotraumas	Acute vertigo, nausea, emesis, tinnitus, sensorineural hearing loss; often associated with middle ear barotrauma	During descent usually, possible during ascent	ENT evaluation, bed rest, head elevation, stool softeners; consider surgical exploration if symptoms persist
Arterial gas embolism	Stupor, confusion, coma, seizures, focal weakness, visual loss	Within five minutes of surfacing (> 80 percent) or during ascent; significant time-depth exposure not required	100 percent oxygen, United States Navy Table 6 algorithm recompression, supportive care
Inner ear DCS	Acute vertigo, nausea, emesis, nystagmus, tinnitus, sensorineural hearing loss	Within 30 to 60 minutes of surfacing (> 50 percent), 90 percent by six hours; significant time-depth exposure required	Same as above
Cerebral DCS	Confusion, focal weakness, fatigue, visual loss, diplopia, speech dysfunction, gait abnormality, headache	Same as above	Same as above
Spinal cord DCS	Paresthesias/sensory loss in trunk and/or extremities, leg weakness, loss of bowel/bladder function	Same as above	Same as above
Headache (arterial gas embolism or DCS)	Severe generalized headache associated with alteration of consciousness and other signs	Usually develops within minutes of ascent, may persist without recompression treatment	Same as above; analgesics
Headache (migraine)	Pounding, throbbing pain; nausea, emesis, photophobia	Usually precipitated during pre-dive activities or at depth	Avoid precipitating stimuli, dive conservatively, consider prophylactic therapy
Oxygen toxicity	Focal seizures, visual constriction, nausea, emesis, vertigo, paresthesias, rare generalized seizures	Occurs at depth	Reduce depth and oxygen exposure, supportive care, seizure management; see arterial gas embolism treatment