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Negative pressure dives & lung fluid

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Oz freediver
Oct 3, 2001
Hi All,

Yesterday I was practicing mouth fill equalizing - reverse packing on the surface, and around a 1 minute negative at 8m or so.
Did about 3 of them, felt OK, but definitely got more lung squeze then I have felt before.

On surfacing from my last one, my lungs & throat felt irritated & itchy and I had to cough. It felt like I had a chest cold and Phlegm in my lungs. This lasted for quite a few hours, and a couple of times I coughed up a pinky colour, wasn't quite as red as blood.
I did still have the cough & irritation the rest of the day and my diving suffered a bit from this. (deep breathing would make me cough)

I'm reasonably sure I didn't do any damage as I feel good today. (I also have reasonably stretchy lungs as I can equalize with normal valvalsa down to 52m before I "run out of air")
Anyone else have this happen to them ?

Does this sound like the lung filling up with plasma thing that Eric Fattah talks about ?
I think he said it takes a while for the fluid to go away and in the extreme NP dives he did, you can't dive very well after.

If it this was I think it was only pretty minor as wasn't there much fluid but the irritation lasted a long time.

I definitely won't push my negative dives that much before a depth dive as it may affect my performance.

Cheers all.
Pulmonary edema

I think that was a minor pulmonary edema. This can seem weird, because a pulmonary edema is a serious medical condition, but I think freedivers can suffer of it in a lesser way and without serious symptoms I had experienced that with negative dives to 10 m and some friends when allowing strong abdominal contractions.
The reasons are various:
  1. Increased hydrostatic pressure in the pulmonary circulation (blood shift)
  2. Low intersticial pressure due to exhalation and/or contractions
  3. Increased permeabilty due to hypoxia metabolites
  4. Lowering of alveolar pressure at air mouth filling
    If you are doing some exercise it increases hydrostatic pulmonary pressure and prone to edema.
    I´m trying to make an investigation of it, during the National Championships
some medical information

There is a lot of information in the Net about lung barotrauma suffered by scuba divers but freediving related articles I only know this one:

“Lung Squeeze” by Dr. David Sawatzky, (the second half of the article is speaks about specific freediving lung squeeze)


hope you can find some helpful information

Saludos Agustín.

I got the same problem, and I ask other freedivers about this problem in Depper Blue Forum- Freediving training- coughing problem. Take a look!
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Reactions: Pekka

You are describing minor pulmonary edema. Be very careful with this as there is the very real possibility of cumulative damage which, in my case, makes me more prone to squeeze.

A serious squeeze can be fatal. Under negative pressure the extremely thin walls (2 cells) surrounding the aveoli can easily rupture sending air into your blood stream and/or allowing fluid into the area interferring with the gas exchange (O2/CO2). The latter leads to secondary drowing.

I am currently recovering from a serious squeeze that could have easily taken my life. It will affect my relationship with freediving forever.

Perry, please tell me more. What symptoms did you get? What did you do to get that injury?

Is that similar to the squeeze that you experienced during Kirk's clinic in Miami last summer? Was that related to proper warm up time, or are there other issues? Hiw has it affected your relationship to freedivng.
Congrats on the new super long static time! I haven't been able to work on that since the clinic because I have had no one to train with. It sounds like you have made quite a bit of progress.:D

Yes Jon it was similar to last summer only this time I had been training regularly for several months. Early on I experienced one bad squeeze. A month or so after that I managed several deep dives with no negative effects or symptoms whatsoever.

Then two weeks ago I had this most recent injury. I believe accumulated tissue damage (from previous squeezes) and increased negative pressure from uncommonly strong contractions caused by attempts to re-capture the expanding air in my mask contributed to its severity.

(The intent was a subtle inhalation but as soon as I opened the airway the neg. pressure forced huge contractions)

Within 30 seconds of surfacing I was choking on the fluid the neg. pressure had forced into my lungs and could hardly pass air. Once back on shore the edma was interferring with what little gas exchange was able to take place and for the next hour the slightest movement inducing choking.

Somehow I managed to get my suit off and myself into the car where I concentrated on consistent shallow breathing until I felt enough reabsorbtion had taken place that it was safe to move around again. Needless to say with secondary drowning being a very real possibility I had a mostly sleepless night.

For a week I could not walk up a flight of stairs without shortness of breath and chest pain. Now, two weeks later, I am still swollen inside and the instant I walk by a cloud of smoke or into a bar I feel it.

I expect a full recovery and the effects of the edema to pass soon. That being said I have either a natural, developed or both physiological sensitivity to atmospheric pressure. It is also likely that I have incurred a fair amount of tissue damage. These factors will severly limit my ability to safely dive to anything but modest depths.

Since this incident I have been consulting with Dr. Claes Lundgren, author of 'The Lung at Depth' and the world's foremost researcher on this topic. It is our hope that we will come to understand all of the causes of my increased sensitivity however in the meantime I have been told to find a new sport...
Did you dive alone!?!?

Anyway, it sounds just like people I know who bleed from their lungs. When they dive deeper than they have done before, they sometimes spit blood and they say the feel like an 80 year old man. Some say the blood comes from the throat and when it comes down to the lungs, they cough.

At what dept did you reinhale the air from the mask? Strange thing that you had negative preassure in your lungs when you reinhaled the air. Most people reach their residual volume at 40 meters, and after that their lungs become negative pressurized. And at 40 meters, their isnt so much air in the mask to reinhale???

You should always get your butt to a hospital if you think you'll suffer from secondary drowning.. some of my friends took a month to recover, some took a day. Hope you recover soon.

That sounds pretty serious. Have you been to a local doctor? Did their eyes roll back in their head when you described what you were doing?:D

Have you been back in the water since then? Maybe it will just take a winter of snowboarding, not freediving, to get your lungs back to their normal state.

I have found that I am MUCH more sensitive to smoke since I started freediving on a regular basis.
I can tell if some smoking from at least a block away- outside. I have never been a smoker, but I find it much more offensive than I did before.
Have any other freedivers, who don't smoke;) , noticed an increased sensitivity to smoke?
My wife is probably getting sick of me complaining about smokers in the car in front of me, but I can smell it right through my cars ventialation system. As soon as the other car truns off i can breath easy again.

Good luck on a speddy recovery.


You're correct that neg. pressure usually occurs around 40m, in my case however it happens earlier. This 'sensitivity' is unexplained and the very thing that has attracted the attention of Dr.'s Lundgren and Sawatzky whom I have been in regular dialogue with.

Thanks Jon for the concern. I am taking time off and yes, I too smell smoke from cars ahead. My ex-wife got pretty tired of my complaining as well and especially disliked it when I pulled cigarettes out of peoples hands. Don't complain too much, it only makes you miserable...
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