Hi,
I have been getting these terrible headaches since I started diving. I have
no problems in terms of equalizing. I feel the headache in the background
(well I can not call it headache at this stage) during underwater. The
headache actually starts as soon as I get on the boat. They are so painful
that I consider to quit diving. The headache improves within the first 24
hours and may last as long as a few days though not as intense. I do not
have migrane and rarely get headaches in my regular life.

My former instructor (PADI) thinks it is due to heavy breathing underwater.
I observed that a lot of effort underwater is open invitation to my
headaches but I always tend to get them whether or not I stay calm
underwater (it helps, though) and exit water with a lot of reserve air.

Yes, I have seen an ear, nose and throat specialist.

Are there other people out there experiencing the same problem? What might
be the reason for my headaches? What can I do? Thank you in advance. I am
awaiting your answers.

Regards.