Take 10 or 15 minutes and notice your breathing as you go about your normal life. You'll probably discover that there are times when you are involuntarily holding your breath. Try to figure out why you might be doing this. Usually, breath holding occurs under stress or threat. It can also occur when we are anticipating something or wanting something to happen: this is the origin of the phrase, "Don't hold your breath!" when expected things may not come true.
Holding your breath doesn't mean a complete cessation of breathing, although that sometimes occurs during nail-biting moments in real life and in the virtual world of fiction and film. More typically, holding your breath means that your breathing is restricted because of increased tension in the muscles responsible for breathing. These include the thoracic diaphragm and some of the abdominal, chest, neck, and shoulder muscles. The primary muscles of inspiration are the dorsal (back) intercostal muscles (which increase or decrease the spaces between the ribs) and the active downward expansion of the diaphragm. The diaphragm is always the first muscle to contract, followed by the intercostals, and later by accessory muscles in other parts of the neck, chest, and abdomen.
During relaxed breathing, the muscles are working primarily during inspiration, expanding the chest cavity to allow the lungs to take in air. Relaxed expiration, on the other hand, is primarily passive, the relaxation of the principal inspiratory muscles. Relaxed breathing also has a detectable expiratory pause, a cessation of movement in the breathing muscles at the end of an expiration. A longer expiratory pause indicates greater relaxation, while a short or non-existent expiratory pause indicates a sense of threat.
Effortful breathing, on the other hand, occurs in states of threat when there is contraction of breathing muscles through both the inspiration and expiration (indicative of sympathetic arousal), and generally higher levels of muscle tension in the body. This feeling of having to force the air out of the body is a kind of holding, or holding on to, the breath. If you do actually hold your breath, it is most likely at the end of an inspiration, meaning that the muscular control of expiration has become extreme.
Chronic breath holding and effortful breathing are not healthy because the muscular effort, coupled with the effects of stress on the nervous, hormonal, and immune systems, can impair both physical and psychological function.
How can you help yourself overcome breath holding habits? One way is to take classes that have a component of breath awareness and control training, like yoga, tai chi, or meditation. These have the effect of activating the parasympathetic nervous system, replacing effortful with relaxed breathing, reducing pain, anxiety and depression, and enhancing re-engagement in everyday and occupational activities. Breathing meditation has been shown to have a positive impact on a variety of conditions including anxiety, depression, PTSD, mood disorders, addictions, and stress tolerance. Breath control has also been shown to reduce pain in childbirth and require less medical intervention.
But you don't need to specifically train your breathing to change your breathing patterns. Activating your body sense related to any internal sensation or emotion will lead to more relaxed breathing. Different emotions are associated with effortful vs. relaxed breathing, as well as with different variations of depth, duration, and rate of breathing.
Anger and fear are associated with effortful breathing patterns accompanied by tension in the abdomen and chest. Chronic and unresolved anger, aggression and hostility in childhood and adulthood is associated with breathing disorders such as asthma and shortness of breath, as well as cardiovascular disease.
Getting in touch with the body sense of pain and emotion in therapeutic and close interpersonal relationships can lead to more relaxed breathing, usually accompanied by sighing and feelings of relief and lightness. I actually think that breath control and breath meditation does not directly affect the breath, but works indirectly through the body sense neural networks (interoception and proprioception) that—when we slow down and pay attention to ourselves in the present moment—stimulate whole body relaxation via reduction of stress hormones and activation of the parasympathetic nervous system. Paying attention to the breath is really no different from paying attention to anything in our bodies.
So, if you are waiting to exhale, making an effort to re-start your breathing when you become aware of it may not be helpful to you in the long run. In fact, the more you try to control your breathing, the more effortful it will become. It would be better to simply feel more deeply into your body state when you notice your breath getting tense: to activate your body sense. Rosen Method Bodywork practitioners, as well as some somatic psychotherapists, can help you to notice your body state when the practitioner senses, through touch, that your breathing has become more effortful or tense. Is there anxiety or fear? Longing or desire? A feeling like you are stuck and can't move?
Marion Rosen's fundamental and powerful insight is that your breathing will ease and relaxation will spread into your body if, and only if, you can actually feel the sensations and emotions in your body at that very moment. You might have a cognitively based insight that your breath becomes constricted because, as a child, your wishes were rarely granted and you are still waiting—holding your breath—for something good to happen. Nice. But unless your breath and body spontaneously relax, then your insight—while pointing to something that may have been the case for you—is not really related to your breath holding. You'll have to go deeper, try again, or find a therapist who can guide you.
The real body sense—the body sense experience that is true for you in the present moment of experience—is always heralded by a relaxation response. And this is why real body sense explorations are so conducive to health and well-being. Relaxation improves breathing and thus blood flow, promotes the cleansing of toxic stress hormones, and enhances immune function. A good cry, a deep meditation, a real encounter with one's fullest sensations of fear or joy, or moving and exercising with awareness: these are all equivalent forms of activating your body sense for improved health.