Ok. It seems to be a fairly poorly localized pain in the retrosternal area served by what's called the T1-T4 nerve complexes. The structures involved are mainly cardiac and esophageal.
Of course, one must first of all respect a possible cardiac cause. Having the event occur during the early morning adds a factor to that concern. If the pain was dull-heavy or squeezing-like, see your doctor asap.
Another possibility (and probably the most common one) is a reflux-like event. This is sometimes associated with the relaxation and lying position of sleep. The pain tends to be sharp and burning. Air swallowed during diving could provide back pressure to burp stomach contents into the lower esophagus. Drinking water, as when taking pills, may wash the acids back down, providing some pain relief.
Lastly, it is possible that the pain could've reached upward from lower down (T5-T6). Structures here include the diaphragm, gallbladder, pancreas, stomach, and the small intestine. The diaphragm especially could've been overworked during the new diving activity, with the irritation/inflammation building overnight.
Conservatively, I'd suggest having a health check as soon as possible, mentioning this event. Of special concern is an assessment of cardiovascular risk.
Of course, one must first of all respect a possible cardiac cause. Having the event occur during the early morning adds a factor to that concern. If the pain was dull-heavy or squeezing-like, see your doctor asap.
Another possibility (and probably the most common one) is a reflux-like event. This is sometimes associated with the relaxation and lying position of sleep. The pain tends to be sharp and burning. Air swallowed during diving could provide back pressure to burp stomach contents into the lower esophagus. Drinking water, as when taking pills, may wash the acids back down, providing some pain relief.
Lastly, it is possible that the pain could've reached upward from lower down (T5-T6). Structures here include the diaphragm, gallbladder, pancreas, stomach, and the small intestine. The diaphragm especially could've been overworked during the new diving activity, with the irritation/inflammation building overnight.
Conservatively, I'd suggest having a health check as soon as possible, mentioning this event. Of special concern is an assessment of cardiovascular risk.
