The cleansing practices: which are reasonable and which are not

The hatha yoga texts describe six categories of cleansing practice, collectively the shatkarma. They vary enormously in risk, and treating them as a single category is the mistake.

Neti: nasal cleansing

The most widely practised and the one with the best evidence.

Jala neti is saline nasal irrigation using a small pot. This is essentially the same as the nasal irrigation recommended in clinical guidance for chronic rhinosinusitis and allergic rhinitis, where the evidence for symptom improvement is reasonable.

The critical safety point: use only sterile, distilled, or boiled and cooled water. Never untreated tap water.

Rare but fatal infections with Naegleria fowleri have occurred following nasal irrigation with untreated tap water, and public health authorities have issued specific warnings. This is a documented risk, not a theoretical one.

Use an isotonic saline solution, clean the device after each use and allow it to dry, and stop if you develop pain or bleeding.

Sutra neti, passing a thread or catheter through the nasal passage, is a different matter — it carries risk of trauma and bleeding and should only be learned in person from an experienced teacher, if at all.

Dhauti: cleansing of the digestive tract

A broad category, and the risk varies enormously within it.

Vaman dhauti involves drinking large volumes of salt water and inducing vomiting.

This carries real risks: electrolyte disturbance from salt water ingestion and from vomiting, aspiration, oesophageal injury, and dental erosion with repeated practice. Cases of hypernatraemia from salt water ingestion are documented.

It is particularly inappropriate for anyone with a history of eating disorders, where induced vomiting is a core symptom, and for anyone with reflux, oesophageal disease, cardiovascular disease, hypertension or kidney disease.

Vastra dhauti, swallowing a cloth and withdrawing it, carries risk of injury and of the cloth becoming impacted. This should not be attempted without direct expert supervision, and there is no evidence of benefit that would justify the risk.

Shankhaprakshalana, drinking large quantities of salt water combined with specific movements to flush the digestive tract, produces substantial fluid and electrolyte shifts and should not be undertaken casually.

Basti: enema practices

Traditional yogic basti and Ayurvedic basti differ in method.

Enemas carry risks including perforation, infection, electrolyte disturbance and dependence with repeated use.

They have legitimate medical indications, administered appropriately. As a routine practice for wellness they are not supported, and the risks are real.

Nauli and kapalabhati

Nauli, the isolation and rolling of the abdominal muscles, requires substantial training. It is contraindicated in pregnancy, hernia, recent abdominal surgery, and abdominal disease, and it should be learned in person.

Kapalabhati, forceful rapid exhalation, is discussed in our article on pranayama. It produces hyperventilation and is contraindicated in pregnancy, uncontrolled hypertension, cardiovascular disease, hernia, epilepsy, glaucoma and recent surgery.

Trataka

Steady gazing at an object, frequently a candle flame.

Low risk. The main considerations are eye strain and, for anyone with an eye condition, avoiding prolonged staring. Some small studies report effects on attention measures.

Not appropriate for anyone with epilepsy where flickering light may be a trigger.

The general problem with these practices

The rationale offered for them is removal of impurities and preparation of the body for further practice — a framework internal to the tradition.

The physiological claim that they detoxify is not supported. The body's elimination systems are the liver, kidneys, gut and lungs, and none of these practices improves their function.

Where a practice has demonstrable benefit — nasal irrigation for sinus symptoms — it is for a specific mechanical reason unrelated to the traditional rationale.

The reasonable position

Nasal irrigation with sterile water is well supported for specific respiratory conditions and is a genuinely useful practice.

Trataka is harmless.

The remainder range from carrying real risk to being clearly inadvisable, and none has evidence of benefit that would justify the risk for a healthy person.

Anyone considering the more involved practices should do so only under direct supervision from an experienced teacher who takes a medical history, and should discuss it with a doctor first if they have any medical condition or take any medication.

Use only sterile, distilled or boiled and cooled water for nasal irrigation. Do not undertake induced vomiting, extended salt water ingestion or enema practices if you have cardiovascular, kidney or gastrointestinal disease, hypertension, are pregnant, or have any history of disordered eating.