The Bodily Channels

What a channel isस्रोतस्

A srotas is a channel — a passage, duct, or conduit through which something in the body flows. The word comes from the root sru, “to flow.” And here is the great insight: in Ayurveda the body is understood as nothing but an immense system of such channels. “The body is a collection of innumerable srotas.”

Everything that lives is something in motion — and everything that moves, moves through a channel. Air, water, food, the seven tissues, the three wastes, even the activity of the mind — each travels and transforms within its own channels. The channels are also where the tissues are made: the nourishment of one tissue into the next happens inside the srotas, as a stream feeds the fields it passes (the field-and-canal model).

This makes the channels central to both health and disease. So long as each channel carries the right thing, in the right amount, in the right direction, the body thrives. Disease, in Ayurveda, is very often simply a channel gone wrong.

From the visible to the unseenstructure of a channel

Srotas span every scale. The gross channels (sthula srotas) are the large, visible passages — the gut, the blood vessels, the airways. The subtle channels (sukshma srotas) are finer and finer, reaching down to the spaces within and between cells. From the windpipe to the most delicate capillary of nourishment, all are srotas.

Every channel has three parts:

Knowing a channel’s roots matters most, because that is where a Vaidya looks first when a channel is disturbed.

The major channelsprabhāva srotāṃsi

The Charaka Samhita names thirteen principal channels, falling into three natural groups: those that bring in life’s essentials from outside, those that build and carry the seven tissues, and those that carry the wastes out. Each is listed with its roots (mula).

The Sushruta Samhita counts the channels somewhat differently — as eleven pairs, with some roots assigned to other organs. OmAyurved follows the Charaka enumeration of thirteen, the most widely taught.

The channels of mind & creationbeyond the thirteen

The classics name further channels for functions the thirteen don’t cover:

• Manovaha srotas (मनोवह) — the channels of the mind, carrying thought and mental activity. Their disturbance underlies disorders of the mind; their health is the ground of clarity and a steady psyche.
• Artavavaha srotas (आर्तववह) — in women, the channels carrying the menstrual flow, rooted in the uterus and its vessels; central to menstrual health and fertility.
• Stanyavaha srotas (स्तन्यवह) — in nursing mothers, the channels carrying breast milk.

With these, the network is complete: from the breath we draw to the children we bear to the thoughts we think, nothing in the body lies outside a channel.

The four ways a channel failsस्रोतोदुष्टि · srotoduṣṭi

Remarkably, Ayurveda holds that all channel disorder takes one of just four forms. Whatever the disease, when a channel is at fault it has either too much flow, too little, a knot, or a wrong turn:

What damages a channelस्रोतोदुष्टि हेतु

Channels are injured by the same logic that governs all of Ayurveda — by an excess of qualities similar to the dosha that vitiates the channel, and by conduct contrary to the tissue or substance it carries. In practice, the great culprits are:

• Ama — the sticky, undigested residue of weak digestion. Ama is the foremost blocker of channels; it clogs the pathways and is the seed of countless disorders. (See Ama.)
• Improper diet and conduct — food, activity, and habits opposed in quality to the channel’s healthy function.
• Suppressed urges — holding back the natural eliminations obstructs the waste channels directly.
• Aggravated doshas — a provoked dosha entering a channel disturbs whatever that channel carries.

Signs a channel is disturbedhow each speaks

Each channel announces its trouble in its own way — usually as some version of the four faults, expressed through what that channel carries. A guide to the major channels:

The great channel & how disease lodgesमहास्रोतस् · खवैगुण्य

One channel stands above the rest: the digestive tract, the mahasrotas or “great channel.” As the body’s central conduit and the home of digestion, it is where most disease begins — which is why Ayurveda watches the gut so closely.

The channels also explain where a disease takes hold. As an aggravated dosha spreads through the body, it settles not at random but wherever it finds a weak spot in a channel — a khavaigunya, a defect or vulnerability. There the dosha and the tissue meet, and disease takes form. This is the localisation stage in the unfolding of illness (described in the six stages of disease), and it is why two people with the same provoked dosha may fall ill in entirely different ways — each at their own weakest channel.

Keeping the channels clearस्रोतोशोधन

If health is unobstructed flow, then much of staying well is simply keeping the channels open. The means are familiar by now, because the whole of Ayurveda points the same way:

• Guard the digestive fire so little ama forms to clog the channels;
• Move the body daily — movement, gentle sweat, and breath keep the channels patent;
• Never suppress the natural urges, which keeps the waste channels flowing;
• Eat and live in tune with your constitution and the season, avoiding the excesses that injure particular channels;
• Cleanse when needed — fasting, lightening (langhana), and, under guidance, deeper purification such as Panchakarma clear channels that have become blocked.