scuba affects body and brain

This article is one of seven on the topic of overcoming panic in scuba diving.  In this article we consider how scuba affects body and brain. Panic is a complex issue, and it is important to explore what is happening for each diver.  This series is simply an introduction to help people raise discussions about their experiences and seek appropriate support.

If you have ever seen a diver panic, or experienced this yourself, you will know how irrational a person is during this state.  It can be rather alarming, and also confusing. You may wonder “why didn’t they accept help?” … “what were they thinking rushing to the surface like that?”.  The fact is they were not thinking.  They may not even have any memory of the incident, because their brain wasn’t taking on board information.  This is due to the way the body and brain work during high stress states. 

Understanding how panic affects body and brain

Panic is both psychological and physiological: mind and body.  You need to understand both in order to understand the panicked diver.  Breathing on scuba when diving affects body and brain. When humans face a threat (or they perceive themselves to be in danger) the nervous system sets off an alarm. This triggers a cascade of reactions in the body and brain to (in theory) address the threat.  It winds the person up into a fight or flight state, in which heart rate and breathing is faster.  The person may be (not always) having thoughts and images of being in danger, this further winds up the system.  This is not panic yet. 

Panic happens when we don’t see a way out

A person in a state of high alert, who is able to take action to fix the problem will be able to calm down, because they can see the threat has passed.  Can you remember that feeling when you don’t recover your reg first time? You start to get a little stressed, but then you get it, or remember your alternate, and its all fine again? It’s like that. Once you see that you know how to fix the problem, you don’t panic, you fix the problem.

The lead up to panic starts when the person perceives threat, but can’t identify what the threat is or doesn’t have the means to resolve it.   As discussed in the previous article, if you know how to fix the problem, you fix it.  Underwater, where you can’t breathe without equipment, there is increased pressure to fix the problem… and you may not even know what the issue is that is causing you stress (e.g. an overly tight exposure suit constricts breathing).  

​​When your mind can’t see what needs to be done, then it ramps up the fight or flight response. It starts with”something is wrong, lungs – breathe faster, we need air, heart – pump harder. We need oxygen to the muscles, we need to get ready to deal with this, whatever it is?!?” Okay, so now the body is in a state of high stress, the brain picks up on this (through nerves/hormones etc.). The alarm system of the brain is increasingly convinced that there is something catastrophically wrong, … so the alarm increases.  But you still can’t see how to fix the problem and so are becoming even more alarmed. 

Panic drives the body and brain into a positive feedback loop

This is called a positive feedback loop, and most likely winds faster in diving, because the air that we are breathing is denser and this creates additional physical stresses.  Gas density when breathing at depth, on scuba, affects body and brain. If this keeps going, the brain goes into a state where actions are driven by it’s most basic parts.  In very simple terms, the thinking bit of the brain is disconnected. The emotional part can take over and drive the bit that is in charge of moving the body involuntarily.  And now the diver is unthinking, and their body is doing whatever it takes to escape the situation.

Unfortunately, the emotional part of the brain is non-verbal, so it does not take into account rule like “no faster than “18 metres per minute”, it also doesn’t know that the thing in your mouth is supplying air … it may even decide that this is an obstruction to breathing, and direct your hand to remove it!

Calming the body and brain to stop the panic

Once a person has entered this state, it is virtually impossible for them to calm themselves.  It is a rescue situation.  A panicked diver is vulnerable as their own actions may cause them to make the situation worse.  It is true that these actions make no sense, but that is because the person was physically incapable of performing rational thought.  Before entering a panic state, it is of course possible for a person to regulate their emotions and thoughts in order to stay calm and aware, and we will cover how people do this in the next two articles.  It is the early stages of responding to stress in which we still retain the ability to think, and can use it to prevent panic. 

If panic, anxiety or any other mental health concern is an issue for you, then seek advice from an appropriate professional (e.g. your doctor, or other healthcare worker).  For scuba diving training and advice on your diving, contact your instructor.