(Medical) questions

Every now and then there is a (medical) question that everyone wants an answer to. We will post these below.
Do you have a question? Ask us via the contact form.

The Deco beer

Author: Franka Appelman

Created: 01 January 2021

Last weekend I had a diving trip with a boat. After the dives, the term 'deco beer' came up regularly. It was sunny and warm (around 30 degrees), diving makes you thirsty, so a nice cold beer is part of that. But why is this now called a deco beer?

As you know, nitrogen bubbles are created during diving. Even if you dived within the deco times and adhered to the safety stop, you will surface with nitrogen bubbles. These are located throughout the body and are gradually cleared by the body during the hours after the dive. If there are too many nitrogen bubbles in the tissues and they cannot be cleared away properly, physical complaints can arise; decompression sickness.

Alcohol is a risk factor for decompression sickness. There are several theories about this, of which fluid withdrawal and vasodilation are the most important.

Alcohol dehydrates the body, making you dehydrated. With dehydration, the blood is thickened and blood flow is reduced. The gas exchange can take place at a reduced rate, so that the nitrogen bubbles are discharged more slowly.
In addition, alcohol has a vasodilating effect that changes blood flow. The nitrogen bubbles that were still nicely stored and anchored in the tissues are given every opportunity to flow through and end up in places where they can cause damage and misery.

From a diving medical point of view, the advice is therefore to avoid the deco beer to reduce the risk of decompression sickness, especially in the first hours after the dive.

An extra note: the deco beer is about alcohol after diving. Alcohol before diving or in between dives is definitely not a good idea! In addition to the risk of decompression sickness, alcohol is known to impair judgment. You don't drive under the influence; don't go diving under the influence!