Many divers know the abbreviations: DCS, AGE, DCI. They often appear in the margins of our dive briefings somewhere between "safety stop" and "good team behavior". But we usually only realize what they really mean when it's too late.

This article is about exactly that:

What is DCI? What happens in the body? And how can you protect yourself?

DCI stands for "Decompression Illness". The term covers two very different but closely related medical emergencies in diving:

DCS (Decompression Sickness):

Bubble formation in the tissue due to dissolved gases, usually nitrogen or helium.

AGE (Arterial Gas Embolism):

Air bubbles that enter the arterial system directly as a result of pulmonary barotrauma - often due to a too rapid ascent without exhalation.

Both forms of DCI have one thing in common:

They can put you in danger very quickly and very seriously.

During a dive, inert gases (mainly nitrogen or helium) dissolve in your body tissue. The deeper and longer the dive, the more gas is stored.

The ambient pressure drops during ascent.

Wenn der Aufstieg zu schnell oder die Dekompression unvollständig ist, kann das Gas nicht schnell genug abgeatmet werden bildet es Blasen.

These blisters can:

• Gelenkschmerzen auslösen

• Neurologische Ausfälle verursachen

• Dein Rückenmark oder Gehirn angreifen

Anything is possible, from mild discomfort to paralysis.

AGE is usually caused by pulmonary overpressure injuries:

For example, if you ascend too quickly in a panic and hold your breath.

The result:

Air bubbles enter the arterial system directly.

They often block blood vessels in the brain.

Symptoms can be:

• Plötzliche Bewusstlosigkeit

• Schlaganfall-ähnliche Ausfälle

• Atemnot

• Herzstillstand

And usually within minutes.

In reality, it is often difficult to distinguish between DCS and AGE.

The symptoms overlap.

This is why many diving physicians simply refer to DCI,

because the initial treatment is the same for both:

• Sofortige Sauerstoffgabe

• Notruf

• Druckkammer-Therapie (HBOT)

The following factors significantly increase your risk:

• Zu schnelle Aufstiege

• Auslassen von Deko-Stops

• Kälte

• Dehydration

• Körperliche Anstrengung direkt nach dem Tauchgang

• Bereits vorhandene Gefäßanomalien (z.B. PFO  ein offenes Foramen ovale)

About 25% of all people have a so-called PFO:

A small hole between the atria that can channel venous bubbles directly into the arterial system.

Particularly risky:

Even with perfectly submerged profiles, such microbubbles can trigger neurological symptoms.

Wenn du wiederholt ungeklärte Deko Probleme hattest lass dich auf ein PFO testen.

Look out for the following symptoms after each dive:

• Gelenkschmerzen

• Hautrötungen oder Juckreiz

• Taubheitsgefühle

• Muskelschwäche

• Schwindel

• Atemnot

• Plötzliche Erschöpfung

Wenn eines davon auftritt: Don't wait - act!

Here are the most important preventive measures:

✅ Slow, controlled ascent

✅ Observe deco stops

✅ Stay warm in the water

✅ Be well hydrated

✅ Avoid exertion after the dive

✅ Don't be afraid of aborting a dive

And if you belong to the risk groups:

✅ Have yourself checked for PFO.

DCI ist nicht nur eine Theorie aus dem Tauchkurs. Es ist eine reale, potenziell lebensbedrohliche Komplikation die dich selbst bei scheinbar harmlosen Tauchgängen treffen kann.

Planning, mindfulness and self-control are your best tools.

And if you have the feeling that something is wrong:

Breathe.

Think about it.

And get help.

This article is based on current findings from the specialist literature, including the work of Simon J. Mitchell (2024).