(...) The following have been rarely reported:
- Nerve or vertebral disc damage — Caused by prolonged postures, sometimes involving the legs.
- Eye damage and blurred vision, including worsening of glaucoma — Caused by increased eye pressure with headstands.
- Stroke or blood vessel blockage — Caused by decreased blood flow to the brain or other body parts from postures.
There is a case report of a woman who presented with pneumothorax (potentially dangerous air around the lung) caused by a yoga-breathing technique called Kapalabhati pranayama. There is another report of a teen-age girl who died of obstructed breathing associated with mouth-to-mouth yoga (in which one person breathes into another person's mouth using yoga breathing techniques).
However, a long-acting barbiturate (which can cause decreased breathing) may have been partially at fault. Chronic cheilitis (inflammation of the lips) and persistent reflux have been reported in yoga instructors with unclear relationship to this modality.
People with disc disease, fragile or atherosclerotic neck arteries, a risk of blood clots, extremely high or low blood pressure, glaucoma, retinal detachment, ear problems, severe osteoporosis or cervical spondylitis should avoid some yoga poses. Certain yoga breathing techniques should be avoided in people with heart or lung disease.
Some experts advise caution in people with a history of psychotic disorders (such as schizophrenia), because there is a risk of worsening symptoms, although this has not been clearly shown in studies.
Aetna InteliHealth. The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.