Depth induced headaches

[Duke Dive Medicine]

It sounds like your friend is describing the location of the mastoid process.

DDM can certianly shed more light on this theory - but apparently mastoid cells with poor pneumatization can cause ear barotrauma.

“Risk factors for MEBt include poor ET function and poor mastoid pneumatization“

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6147252/“

Perhaps as the depths get great enough the added pressure causes pain in the mastoid process as a referred pain from the ear itself?

You read my mind. Was waiting to hear back from the OP about exact location before formulating theories but I was thinking about both of those.

Best regards,
DDM

 

[Angelo Farina]

Shallow breathing, or skip breathing causes headaches. Breathe deeply and slowly.

Exactly.
Back head ache is a typical symptom of a CO2 intoxication, which is usually due to inproper breathing pattern.