Why does the thyroid cease to function correctly? There are various reasons. Some people say that lack of iodine in one’s diet can lead to enlargement and faulty operation of the thyroid. An essential constituent of thyroxin is iodine. If this is not sufficiently abundant in the food that one eats, then the thyroid is unable to manufacture suitable amounts of thyroxin to meet the needs of the body. There seems to be a lot of truth in this idea, for in areas of the world where the iodine content of the soil is low, there are higher incidences of thyroid problems. There are various iodine tablet supplements on the market which overcome this problem.
Another cause of malfunctioning of the thyroid is bad or sluggish blood circulation.
This can be caused by a sedentary life and general lack of exercise. If the blood in the thyroid gland (as well as any other part of the body) is devitalized or insufficient, then it cannot receive proper nourishment and it cannot flush out impurities. It becomes ineffective and consequently the health of the body suffers. It is here that sarvangasana contributes directly to improve the efficiency of the thyroid and in turn the entire body. The inverted position of the body directs a good blood flow to the thyroid gland under the action of gravity. Furthermore, the curvature of the neck in the final pose tends to restrict the normal flow of blood to the brain through the external carotid arteries. This flow is redirected into the thyroid gland. Thus for the duration of the asana, the thyroid is flushed and nourished with an extra supply of blood, which helps to improve its functioning.
A third important factor in faulty functioning of the thyroid is emotional stress. Many people start to develop thyroid problems after they have suffered emotional shock or when their stress level in life becomes too great. The social pressures of exams, business, worrying about what the neighbours think and so many other factors of modern life tend to upset the balance of the body. The thyroid is directly controlled by the pituitary gland, the master controller of the endocrinai system. The pituitary gland, in turn, is controlled by the brain and the mind. Thus mental stress and dissatisfaction lead to imbalance of the pituitary gland, which leads to general disruption of the entire hormonal system, including the thyroid gland. It is here that yoga can again help to normalize the system and bring the thyroid into balance. Through all yoga practices one can attain deeper states of relaxation, whether temporarily or permanently, which helps to harmonize the hormonal system, including the thyroid gland. The body has an innate tendency to repair itself and establish equilibrium if, and only if, it is given a chance. It receives this chance during periods of yoga practices. It is also worth pointing out that sarvangasana is a simple and yet effective asana for inducing quick relaxation. It is for this reason that sarvangasana helps to integrate and normalize the operation of the thyroid gland.
Thus we can summarize by saying that the thyroid is a vital organ of the body. If it starts to function incorrectly, then the whole body will also suffer. Sarvangasana brings about health of the thyroid in two ways: firstly, it directly improves the physical condition and functioning, and secondly, it helps to reduce excessive emotional and mental stress, which tend to interfere with its operation. It is not without reason that sarvangasana is regarded as one of the best of the yoga asanas, for its benefits are many.