Is it trachea squeeze?

[Chhan871]

I've had this recurring issue when doing multiple deep dives in a training session where at the end of the session, there's blood in my spit. I don't mean after my last dive either - I mean back on land a good 30 minutes after my last dive. Like clockwork, the blood in the spit comes. What could this be? I thought trachea or lung squeeze would yield a more immediate symptom. This ONLY happens after doing several 30+ meter dives. I can do 20 or more shallower dives and it won't happen. Also when it happens, it clears up in an hour or so.. no more blood in the spit. I've taken time off, up to a month, and it just seems to keep coming back no matter what. Any insight would be highly appreciated

 

[puett66]

I checked ChatGPT and see the response below. I was a paramedic x 20 years and this seems very logical. I am not a free diver nor a physician. But I think you need to get checked out per the below.

=== ChatGPT Generated Content ===
That’s a very concerning symptom, and you’re right to notice the pattern and question it. Blood in the spit after multiple 30 m+ dives—even if it’s delayed by 30 minutes and clears in an hour—points toward a mild but recurrent form of pulmonary barotrauma (lung squeeze or tracheal irritation) rather than something benign like gum bleeding.

A few things to keep in mind from the freediving/medicine perspective:

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Why it happens more with deeper dives (30 m+)​

• At depth, the alveoli and pulmonary capillaries are under far greater stress than at 20 m. Even with proper equalization, repetitive deep dives create stress failure of the capillaries: tiny leaks of blood or plasma into the airways.
• At shallower depths, your lungs aren’t compressed enough to cross that threshold.

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Why the delay (30 min after surfacing)​

• Lung squeeze symptoms can be delayed. After surfacing, blood and plasma that leaked into alveoli during the dive may take some time to be coughed or cleared upward.
• The effort of recovery breathing and moving around on land can trigger coughing up the blood that was already sitting lower in the airways.

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Why it clears quickly (within an hour)​

• A small, self-limited bleed from stressed pulmonary capillaries often clears once the blood is coughed up and the stress stops.
• That does not mean it’s harmless: repeated microtrauma can lead to scarring, reduced lung compliance, or increased risk of a major squeeze later.

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Key red flags​

• Recurrent pattern despite rest.
• Depth-dependent (only 30 m+ dives).
• Blood in spit = airway/lung involvement (not just sinuses).

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Possible contributing factors​

• Too many deep dives in a single session (repetitive loading).
• Inadequate surface intervals (lungs not fully recovered before the next dive).
• Technique issues (excessive chest stretching, packing, or strong diaphragmatic contractions at depth).
• Individual susceptibility (some divers have more fragile pulmonary capillaries).

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What to do​

1. Stop deep training until you’ve been medically checked. Even if it resolves quickly, it’s lung trauma.
2. See a dive medicine specialist / pulmonologist—ideally with experience in freediving or scuba-related barotrauma. A CT scan, spirometry, or even diffusion capacity test can sometimes show if there’s lingering damage.
3. Reintroduce depth slowly after clearance, with longer surface intervals, fewer repetitions, and conservative depth limits.
4. Log every episode (depth, number of dives, surface interval, exact onset of blood) so you and a doctor can track patterns.

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Bottom line​

Even though the symptoms seem “mild” and predictable, this is not something to ignore. What you’re describing is classic for repeated lung stress/squeeze, and every recurrence raises your risk for a more serious injury. Some freedivers only get away with these warning signs until one dive causes a large hemorrhage and ends their season—or worse.

I strongly recommend you stop pushing past 30 m until you’ve seen a doctor trained in dive medicine, explained your pattern, and had lung imaging/assessment.

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