The Science Behind Hyperventilation

     

     We're about to hit you with some science, are you ready??

   

      The body needs oxygen in order to survive. Whenever a person inhales, oxygen is taken into the lungs where it is picked up by the hemoglobin. Hemoglobin carries the oxygen around the body where it is released for use by the body's cells. The cells use the oxygen in their energy reactions subsequently producing a by-product of carbon dioxide (CO2) which is, in turn, released back to the blood, transported to the lungs, and exhaled. (There will NOT be a quiz on this later!)

     Efficient control of the body's energy reaction depends on the maintenance of a specific balance between oxygen and CO2. This balance can be maintained chiefly through an appropriate rate and depth of breathing. Obviously, breathing "too much" will have the effect of increasing levels of oxygen (int he blood only) and decreasing levels of CO2, which breathing too little will have the effect of decreasing levels of oxygen and increased levels of CO2. The appropriate rate of breathing, at rest, is usually around 10-14 breaths per minute (You're timing yourself as you read this, aren't you?)

     Hyperventilation is defined as a rate and depth of breathing which is too much for the body’s need at a particular point in time. Naturally, if the need for oxygen and the production of CO2 both increase (when you exercise, for example), breathing should increase appropriately. Alternately, if the need for oxygen and the production of CO2 both decrease, (when you are relaxed), breathing should decrease appropriately.

     While most of the body’s mechanisms are controlled by involuntary chemical and physical means (and breathing is no exception), breathing has an additional property of the ability to also be controlled voluntarily. We can hold our breath at will while swimming or speed up our breathing for blowing up a balloon. Therefore, a number of “non-voluntary” factors such as emotion, stress or habit can cause us to increase our breathing. These factors may be especially important in people who suffer panic attacks causing these people to show a tendency to breathe too much. Most of us consider oxygen to be the determining factor in our breathing, BUT the body actually uses CO2 as its “marker” for appropriate breathing. The most important effect of hyperventilation, then, is to produce a marked drop in CO2. This, in turn, produces a drop in the acid content of the blood leading to what is known as alkaline blood. It is these two effects – a decrease in blood CO2 content and an increase in blood alkalinity, that are responsible for most of the physical changes, that occur during hyperventilation...and the spiral begins.

     

     One of the most important changes produced by hyperventilation is a constriction or narrowing of certain blood vessels around the body. In particular, the blood going to the brain is somewhat decreased. Coupled together with this tightening of blood vessels is the fact that the hemoglobin increases its stickiness for oxygen. So, not only does less blood reach certain areas of the body, but the oxygen carried by this blood is less likely to be released to the tissues. Paradoxically, then, while over-breathing means we are taking in more oxygen, we are actually getting less oxygen to certain areas of our brain and body. This effect results in two broad categories of symptoms: 1) centrally, some symptoms are produced by the slight reduction in oxygen to certain parts of the brain (including dizziness, lightheadedness, confusion, breathlessness, blurred vision, and unreality); 2) peripherally, some symptoms are produced by the light reduction in oxygen t certain parts of the brain (including, an increase in heartbeat in order to pump more blood around, numbness and tingling in the extremities, cold clammy hands and sometimes stiffness of muscles). It is important, too, to point out that hyperventilation (possibly through a reduction in oxygen to certain parts of the brain) can produce a feeling of breathlessness, sometimes extending to feelings of choking or smothering, so that it actually feels as if the person is not getting enough air.

     Hyperventilation is responsible for a number of overall effects. First, the act of over breathing is hard physical work. Hence, the individual may often feel hot, flushed and sweaty. In addition, because it is hard work to over-breathe, prolonged periods will often result in tiredness and exhaustion. Third, people who over-breathe often tend to breathe from their chest rather than from their diaphragm. This means that their chest muscle since they are not made for breathing, tend to become tired and tense. Thus, they can experience symptoms of chest tightness and even severe chest pains. Finally, may people who over breathe tend to engage in a habit of repeatedly sighing or yawning. These tics are actually forms of hyperventilation since whenever one yawns or sighs they are “dumping” a large quantity of CO2 very quickly. Therefore, when combating the problem, it is important to become aware of habitual sighing and yawning and trying to suppress these habits.

     An interesting and important point to be made about hyperventilation is that it need not necessarily be obvious to the observer. In many cases, hyperventilation can be very subtle. This is especially true if the individual has been slightly over breathing for a long period of time. In this case, there can be a marked drop in CO2 but, due to compensation in the body, relatively little change in alkalinity. So, the person who is hyperventilating will not demonstrate conventional symptoms. However, because CO2 levels are kept low, the body loses its ability to cope with changes in CO2 so that even a slight changing in breathing (like through a yawn) can be enough to trigger symptoms. This may account for the sudden nature of many panic attacks, and is one reason why may sufferers report that they may not feel  “…as if I’m hyperventilating.”

     Probably the most important point to be made about hyperventilation is that is it not dangerous. Hyperventilation is an integral part of the fight or flight response and so its purpose is to protect the body from danger, not to be dangerous. The changes associated with hyperventilation are those which prepare the body for action in order to escape potential harm. Thus, it is an automatic reaction for the brain to immediately expect danger and for the individual to feel the urge to escape. Consequently, it is perfectly understandable, if there is no obvious danger, for the sufferer to believe the danger may be internal. Nevertheless, this is not so. It is important to remember that far from being harmful, hyperventilation is part of a natural, biological response aimed at protecting the body from harm.