The following people should not perform sarvangasana without seeking expert medical guidance:
- Those who have weak hearts or excessively high blood pressure. Though after a short time the blood pressure is greatly reduced in sarvangasana, initially it is increased. It is the initial increase of pressure that can cause harm.
- People with an excessively enlarged thyroid. Though sarvangasana is a wonderful asana for alleviating and removing an enlarged thyroid, it can cause harmful effects if the thyroid is too swollen and if it is toxic. A person who has an excessively large thyroid should first practise other asanas and yoga techniques under guidance to reduce the swelling. When the thyroid has reduced in size, sarvangasana can be done with great benefit.
- People who have weak blood vessels in the eyes.
- Sufferers of arteriosclerosis.
- Sufferers of cerebral thrombosis.
- People with excessively impure blood. This is something that you must judge for yourself. If you are not sure then seek guidance. A person with experience will be able to tell immediately if your blood is pure or impure. If you are severely constipated or your skin is covered in boils, then this is an indication that your blood is excessively toxic.
- People with slipped discs. It is advisable not to practise sarvangasana if you have this ailment for you may aggravate the dislocation of the spine when raising and lowering the body to and from the final pose of sarvangasana.