The veins of the thyroid gland (thyroid-mandibular, mediastinal, vertebral lateral, paratracheal, paraesophageal, upper, lower veins of the larynx, pharynx, corolla) are paired veins that carry blood from the organs of the neck and upper chest. In most cases, they divert blood from the thyroid gland, returning it to the organs of the head and neck. However, in some cases, the thyroid veins carry blood from other sources than the thyroid gland.
Thyroid veins are formed by the fusion of the deep and superficial thyroid-cervical veins, which appear on the inner surface of the neck. They pass through the thyroid gland and empty into the vena cava. One vein passes to the left, the other to the right, separating the thyroid gland from the trachea.
The three main qualities that determine the function of the thyroid gland are its volume, the level of thyroid hormones in the blood and the size of its residual tissue. You're not the only person, but everyone has a certain optimal level of thyroid activity throughout their lives. It takes years to determine the level required to achieve and maintain health.