The body works best when things are in balance. Oxygen is plentiful in the atmosphere but to get to where it is needed (i.e. the cells where energy is produced), maintaining a certain CO2 level is critical. In fact, unless CO2 levels are in a healthy range between 35 and 45mmHg, the body puts out massive energy to rebalance. When you consider the effects of low CO2 mentioned below, it really is no wonder that the body’s breathing is geared towards maintaining CO2 balance rather than maximising oxygen intake.

1. Low CO2 Makes Blood Vessels Constrict

40% Reduced Oxygen Supply after One Minute of Overbreathing
Image Reference: Litchfield (1999)

Low CO2 affects smooth muscle such as found around blood vessels. This is because increased blood pH forces calcium ions into smooth muscle cells making them cramp. This can severely reduce blood supply – and hence the supply of oxygen and glucose – to the brain and other organs that need it. The picture on the right shows oxygen reduced by 40% after one minute of overbreathing.

Smooth muscle is also found around all other hollow spaces in the body which are similarly affected by low CO2:

  • When lungs and bronchi constrict, feelings of chest tightness develop, wheezing may be heard and asthma attacks are more likely.
  • Constriction of sinuses can lead to chronically blocked nose.
  • When the intestines tighten constipation or diarrhea can result.
  • Constriction of the Eustachian tubes (ear canal) can increase occurrence of glue ear in children.
  • Bladder constriction potentially results in frequent toilet visits at night.
  • Cramping of the uterus can make periods painful and stronger.

2. Low CO2 Increases Blood pH

One might think that a higher pH, i.e. more alkaline, is a good thing – but no – the body prefers its pH within tight bounds, 7.35-7.45 to be precise. pH affect chemicals’ reactivity. Importantly, a higher pH changes oxygen’s binding to hemoglobin making it stick tighter and less likely to release. Hence, less oxygen is available to cells. Full saturation of the blood does not mean that the cells get it, if your CO2 is low. This is known as the Bohr effect.

3. Loss of Essential Minerals

Occasional changes in blood pH are no cause for concern as the body is excellent in looking after itself and many mechanisms exist to rebalance pH. When a hypocapnic state becomes more common, the effects will become more noticeable and stronger over time. One of the reasons is that the body loses its buffering ability.

The two main ways of pH rebalancing are via the breathing and via the kidneys. If blood pH increases, the breathing reflex automatically slows down. If breathing habits continue to override this, blood pH becomes low for longer periods of time and the kidneys activate to flush out mineral buffers (mostly calcium and magnesium). However, these are essential for many other bodily functions, notably energy transfer. Thus, long-term hypocapnia often results in fatigue. One may question what good mineral supplements are, if these are simply flushed out due to dysfunctional breathing? Knowing this can be your secret weapon on the road to health and well-being.

4. Low CO2 Makes Nerves More Excitable

Calcium ions not only constrict smooth muscle but also affect nerve cells which in turn become more likely to fire at will. This not only affects how we perceive the environment (monsters under the bed anyone?) but also our reactions and emotional state. Irritability, attention deficit, irrationality, moodiness, and even seizures can be a result of low CO2.

5. Inflammation and Immune System Response

inflammationAs cell oxygen levels drop cells become more vulnerable, heightening immune system response. Inflammation is one of the first response and can take hold despite the absence of invaders. Long-term inflammation apart from being responsible for conditions such as arthritis, inflammatory bowel, gingivitis, eczema, has also been linked to alzheimers, cancer, depression and cardio-vascular disease, giving inflmmation the name the “secret killer”.

Who would have thought that breathing has anything to do with that!

6. Muscle Tension

Already mentioned above is the effect of low CO2 on smooth muscle and constriction of blood vessels. Reduced blood supply means less oxygen available to muscle cells. Under these conditions, muscles twitch, spasm or cramp more easily and lactic acid builds up resulting in low performance or even pain. Shoulder and neck tension is common in dysfunctional breathers yet normalises when breathing leads to normal CO2 levels.

 

As you can seen the effects of low CO2 are plentiful and far-reaching. This is also why changing how we breathe is often experienced as a major life event: what would happen to you if your brain had more oxygen, your muscles and nerves were more relaxed?

How would your life change if you changed the way you breathe?