Did a 123 min dive, deepest depth 99 ft. Rebreather PPO2 set point was 1.2, using a 24/20 Trimix. Did decompression with a PPO2 of 1.52. Even stayed 5 min longer than prescribed decompression, waiting on buddies. After I got out of the water, I noticed that I had severe cramping (whether it had anything to do with it or not, I do not know) in my feet, ankles, shins hamstrings, lower back & middle fingers on the hands. After about 2 hrs, I noticed that I had some swelling in the breasts, especially the left side. After dinner, it was considerably worse. The left breast was 1-1/2 times normal size. I told my tech instructor the next morning & he told me to call DAN. I did & was instructed to go to the Valdosta South Georgia Medical Center (have a hyperbaric chamber). I went to the ER (arrived about 10 am) & after 5 hrs there, 3 consecutive of which, of which I never saw a soul, while hooked up to an IV (Damned, did I have to urinate), the ER Dr came in & asked me if I knew I was diabetic. I said "no" (runs heavy in my family- both parents & 2/4 of my siblings). The lab tests for the hyperbaric chamber had come back & my blood sugar was at 562 (normal is about 100). It was only a matter of time before I got it... The hyperbaric nurse came up & took me down to the chamber room. After changing into proper garb for the chamber, They put me in & got me under pressure. I did a schedule 6 (3ATA), 5 hour ride. The chambers were acrylic tubes with metal ends. 100% O2 environment with a mask for air breaks. I must admit, I got rather restless the last 3 hours. I am not at all used to being still for that period of time, especially on my back. After a half hour or so at 60ft, the swelling & soreness began to abate, . As I was very slowly brought down & out, the reduction in swelling was reduced by about 75%. When I got out the swelling was down 75%- 80% & pain was down about 90%. I was then taken to ICU about 9:30pm. I guess I missed dinner for the night & had eaten nothing since 8 am. I was so hungry that I could not get comfortable. The nurse was able to bring me a couple of crackers & apple sauce, which allowed me to feel good enough fall asleep. I was woken up twice for blood samples & 2-3 times to reattach leads that had fallen off.. That morning, after breakfast, the hyperbaric Dr came in & told me that I was going back to the chamber that day, while his NP listened to my lungs. Next thing I know, a couple hours later I'm being released. I asked about the mentioned chamber ride & the nurse looked it up & there were no orders. He called the Dr. & the Dr said if his PN put in orders, then it would happen. She did not, so I was let go. The Dr. believes my hit was a result of dehydration caused by the undiagnosed diabetes. I apologize if some of my terms/ words are not correct. I am just telling it as I experienced it. Looks like a lot of lifestyle changes ahead of me. Fortunately the DCS hit did have one silver lining- I found out I was diabetic & can get the care I need to manage it.