I often receive questions from Tibetan Buddhist practitioners about the connections between Tibetan Medicine and the subtle anatomy. Subtle anatomical structures and energies feature strongly in the Completion Stage (dzok-rim) yogas found in advanced forms of Vajrayana practice known as Tsa-Lung Trulkor. These include breath manipulation exercises ((Skt. pranayama)), complex visualizations, and physical yoga techniques.

A basic understanding of Tibetan Medicine is quite valuable in the practice of Completion Stage tantric yoga, so it's worth exploring some of the connections between these two traditions. By understanding our physiology and psychology in terms of traditional science, the juxtaposition of tantric techniques onto the physical body becomes much more seamless and efficacious. In this way, we can better understand Buddhist meditation techniques in terms of "Inner Science" (nang-dön rigpa) as opposed to religion and spirituality, making them somewhat more accessible in modern times.

In Tibetan Medicine, our psycho-physiological organism functions through the actions of the three humoral energies (or three nyépa) - rLung/wind, mKhris Pa/bile, and Bad Kan/phlegm. These energies are the biological amalgamations of the classical Five Elements within our physiology. The Five Elements are themselves considered to be the building blocks of all compounded phenomena - cosmological roots of all observable reality. The essential elements are formless energies, but within a biological system (such as our bodies) they produce the various elements that help to create and sustain life.

These humors can become imbalanced through a variety of causes and conditions. While proximal conditions of disease include circumstances like dietary and lifestyle habits, the fundamental energetic causes of imbalance lie in the three mental afflictions of desire/attachment, hatred/anger, and delusion/ignorance. These afflictive mental states share a common root in ma-rikpa - basic unawareness of our true nature. If there is no mental affliction arising from fundamental unawareness, then the very cause of imbalance is not present and disease is (theoretically, at least) unable to manifest. So on a most essential level, the imbalances of our physical body are a manifestation of our mind, an aggregation of empty elemental atoms that can be affected through Creation and Completion Stage practice.

This topic is wildly vast, and it's advisable for serious practitioners to undertake further study on the topic of subtle anatomy to get the most out of their practice. However, in order to offer a small taste of the profundity of Tibetan tantra, and of Sowa Rigpa, here is a brief interdisciplinary explanation of the three primary focuses of yogic practice: rTsa (channels), rLung (energy), and Thiglé (essential "drops").

rTsa

rTsa refers both to the channels of the physical body (i.e. blood vessels/black channels and nerves/white channels) and to energetic channels which do not have a direct physical correlate. rTsa branch out from the five korlo (Skt. chakras) and produce 72,000 channels through which all kinds of physical and energetic substances travel. In Tibetan Medicine, we recognize a physiological connection between the chakras and the major glands of the endocrine system. The base chakra is connected with the sexual organs, the thyroid with the throat chakra, the crown chakra with the pituitary and pineal glands, etc.

The three main tantric channels (uma, roma, and kyangma) do not have exact physical correlates in a fully-formed body, though some scholars (including Namkha’i Norbu Rinpoche) maintain a connection between the roma channel and the vena cava (the root of the venous system through which only “solar” blood runs), the kyangma channel with the spinal cord (the root of the nervous system through which cerebrospinal fluid flows), and the uma channel with the aorta (the root of the arterial system through which blood flows together with the pervasive wind). Other scholars throughout history have made different associations, most famously (though arguably erroneously) between the spinal cord and the central channel. According to the great 16th century scholar Dr. Zurkhar Lodrö Gyalpo, the real roots of the three channels are found during the 6th week of embryological development, when the growth channel that arises from the navel chakra (which is the combined essence of the father, mother, and the consciousness) subdivides into three channels, which are both the foundation for the various physical channels in the body and the physical manifestations of the three tantric channels. One channel (kyangma) ascends from the navel to form the brain, which arises based on ignorance. One channel (roma) ascends towards the center of the body, producing heat and blood based on anger. And one channel (uma) descends to form the sexual organs, which arise from desire.

There are many different ways of visualizing and categorizing the channels of subtle anatomy, with many lineages saying different things. Tibetan Medicine basically unanimously agrees that the tantric channels do have a physical foundation (otherwise they wouldn’t have physical effects), but that they are not directly observable in an adult body. Therefore it would be incorrect to say that the aorta is the actual uma visualized in tantric practice, but it’s fair to say that the existence of the arterial system is dependent upon the influence of the central channel during the sixth week of gestation. There are many other channels which straddle the divide between energetic and physical reality. The 32 “Dakini points,” for instance, are eight points connected with each chakra, used for treatment and diagnosis of disorders affecting the internal organs. These are similar to acupuncture meridians, but they are also energetically connected with 32 Dakini points located in outer geographic locations on the planet. As the Kalachakra states, “As in the outer, so in the body; as in the body, so in the other.” This implies that the outer and inner worlds are reflections of one another, and that causing harm, or stimulating healing, to these geographic locations ultimately also has an effect on our collective health. What’s more, for tantric practitioners, these “outer” and “inner” experiences are additionally reflected in the “other” - the mandala of the tantric deity.

There are bad channels (tsa ngen) as well as good channels (tsa zang). Bad channels are formed through accumulation of negative karma and habitual patterns. The more negative channels we have, the more obstacles to spiritual practice we’ll experience. And ultimately, an abundance of negative channels can propel an individual into negative successive rebirths. These can be compared with neural pathways created in the brain through habitual activities or thought patterns, though their "karmic" effects can still be experienced after death. Purification practices, such as Vajrasattva, are commonly employed (especially in preliminary practices) in order to eliminate negative "neural pathways" and facilitate the ready experience of enlightenment.

rLung

rLung (pronounced loong) refers both to gross physiological winds and subtle mental wind energies. The gross winds consist of 10 major wind energies in total – the five root winds (life-sustaining wind, ascending wind, all-pervasive wind, fire-accompanying wind, and descending wind) and the five branch winds (which give rise to each of the five senses). These are all intimately linked with our physiological and psychological function. The Life-Sustaining wind (Srog ‘Dzin rLung) is particularly connected with our mental health and memory, being primarily located in the brain and traveling downward towards the heart. Severely imbalanced Life-Sustaining Wind can manifest in conditions bipolar disorder or psychosis, as well as issues relating to memory. But even though other winds like the Fire-Accompanying Wind or Descending Wind may not be directly connected with the mind, if they become imbalanced then they can disturb the Life-Sustaining Wind (sometimes via the Ascending Wind) and produce mental issues. Likewise, when the Life-Sustaining wind is disturbed, it can aggravate the other winds and produce negative physiological symptoms. This is part of the mechanism in the mind-body connection. The subtle wind comprises of impure karmic wind as well as pure wisdom wind (yeshe rLung). Our respiration is primarily karmic wind. But according to the tantras, 1/32 of our breathing naturally consists of wisdom wind. So out of 32 respirations, there will be the equivalent of one natural respiration of wisdom wind. Out of a 100-year lifespan, this amounts to three years, three months, and three days of wisdom wind (which is where the standard retreat parameters originally came from, according to Dr. Nida Chenagtsang). Through rTsa rLung techniques, we can convert our karmic wind into wisdom wind and cause it to enter the central channel, which produces spiritual experiences and ultimately liberation. Wisdom wind is not a humoral energy (nyépa = "defiled energy") arising from clinging and unawareness, because it’s not rooted in dualistic vision and unawareness. But through calming our humoral wind and healing afflictive psychological patterns, we both stop disease and facilitate experiences of wisdom wind.

It’s particularly important that practitioners of completion stage yoga work to control and balance their gross wind energies; otherwise, negative effects can result from directing wind into the central channel, and both physiological and psychological symptoms can manifest. Gross rLung can become aggravated by many conditions – including seasonal/climatological influences, an improper diet (i.e. inadequate nutrition, excess caffeine or sugar, raw foods, carbonated beverages, etc.), too much talking, insufficient sleep, intoxication, sexual depletion, and a number of other circumstances. Good health is foundational for spiritual practice.

Thiglé

Thiglé travels on the rLung. It is the essential energy connected with our mind, and bears a partial medical connection (but not direct correlation!) with our hormones, which move throughout our body and fluctuate with our mental state. It is what moves between our physical and mental realities, traveling throughout the body (via the rLung) from chakra to chakra. Thiglé is produced through the metabolic process, which is responsible for sustenance and perpetual re-creation of our physical body. In Tibetan Medicine (as well as in Ayurveda), the metabolic process is described as taking place in seven major stages, producing what are known as the “seven bodily constituents” (or seven lu-zung). When we eat food, it is first transformed into a substance known in western medicine as chyme. According to Tibetan Medicine, this pulpy mass is processed and used to nourish/compose the blood in the liver via the action of the Color-Transforming Tripa humor. This blood is then gradually transformed into muscular and connective tissue. Muscle is transformed into adipose tissue, which contributes to the formation of bone, which contributes to the bone marrow, which produces reproductive fluids. This is a basic outline of metabolism in Tibetan Medicine, which is a process that takes one full week. For each step of this “pure” digestive process, an “impure” residue is produced that assists in various bodily functions. The impure aspect of the bones, for instance, become our teeth, nails, and hair, while the pure aspect moves on to build and sustain the bone marrow. The reproductive essences, themselves known as “white thiglé” and “red thiglé,” are also further divided into pure and impure aspects. The pure aspect – the most vital essence from our metabolic process – separates from the outer reproductive fluids and settles at the heart, causing radiance and vitality to spread throughout the body. This is the end result for most human beings. However, for tantric practitioners, a further refinement of 10 levels of thiglé is described in tantric sources – including from Machig Labdrön (Chöd matriarch and early student of Traba Ngönshe, the tertön of the Tibetan Medical Tantras). She explains that, through the skillful application of rTsa-rLung techniques, including specialized forms of breath retention, we can manipulate and utilize our wind energies to clarify and refine our thiglé through 10 gradual stages, eventually becoming the ultimate vajra essence of liberation. But without healthy digestion, we won’t have the necessary ingredients for the thiglé refinement process in the first place. Our seven bodily constituents must be healthy in order for the production of healthy reproductive essence and thiglé to take place. The radiance of one’s complexion (both literally and figuratively) is a traditional way of evaluating the health of one’s thiglé, and Tibetan doctors will take this into account in order to determine if a person’s metabolism is pushing nourishment all the way through the seven bodily constituents.

The white and red thiglé also straddle the gap between physiological and spiritual experience. All beings have red thiglé from their mother and white thiglé from their father. Before the umbilical cord is cut, they abide together at the navel chakra of a fetus/baby, assisting in the formation of the body. Once the cord is cut, they separate and the white moves to the crown chakra while the red moves to a position under the navel. These thiglé move on a daily cycle with the sun and moon, which are associated with the red and white thiglé, respectively.

Tripa/bile and pekén/phlegm are not as involved in our subtle anatomy as rLung. But they can still have an effect on our physiological function and ultimately our mind, which of course also affects our experience of the subtle body. Healthy and robust metabolic fire (mé-drö), predominated by fire but generated through a confluence of all three humors, is essential to physiological and spiritual health, especially when practicing heat-related practices. However, an excess of tripa can make us angry and aggressive, preventing us from settling our minds and generating love. Excess pekén/phlegmatic energy, on the other hand, can make us sluggish and lethargic, hampering our clarity and making it difficult to focus. The humors can also influence our dreams, our experiences of meditation, our emotional obscurations, and our overall state of being. So it’s important to really pay attention to humoral balance in tantric and yogic practice.

Recommended Further Reading

Karmamudra, The Yoga of Bliss: Sexuality in Tibetan Medicine and Buddhism - Dr. Nida Chenagtsang

Tibetan Yoga: Principles and Practices - Ian Baker

Being Human in a Buddhist World - Janet Gyatso