What causes thyroid cysts?

Thyroid cyst is a local disease that has a great impact on the lives of patients. The main cause of the disease is iodine deficiency, which leads to thyroid enlargement and thyroid cysts. There are many types of thyroid cysts, some are hemorrhagic, some are colloid, some are necrotic, etc. So, what are the causes of thyroid cysts?

Clinically, thyroid cysts are not actually a single disease. The vast majority of cysts are caused by simple goiters, mainly nodular goiters and degeneration of thyroid adenoma. Only a few cysts have squamous epithelial walls, which may originate from metaplasia or remnants of the thyroglossal duct and the fourth branchial cleft. Some may also be cystic changes of thyroid cancer.

Causes of thyroid cysts

(1) Iodine deficiency or excess in the water and soil in epidemic areas.

(2) Increased iodine requirement (due to growth and development, breastfeeding, cold, infection, poisoning, emotions, etc.).

(3) Goitrogens (cassava, radish, cabbage, thiouracil, thiocyanate, sodium para-aminosalicylate, phenylbutazone, potassium perchlorate, cobalt, and lithium salts).

(4) Drinking deep well water (containing excessive sulfur hydrocarbons, calcium, and fluoride), water sources contaminated by bacteria, etc.

(5) Familial congenital thyroid hormone synthase deficiency. The thyroid tissue has a strong ability to concentrate iodine. The human thyroid gland needs 60-80ug of iodine every day to produce physiologically active thyroid hormones. There is a mutually dependent and mutually restrictive feedback relationship between the thyroid hormone secreted by the thyroid gland and the thyroid stimulating hormone (TSH) secreted by the pituitary gland in the body. When iodine is deficient, thyroid cells cannot synthesize enough thyroid hormone, the concentration of thyroid hormone in the blood decreases, the inhibitory effect of thyroid hormone on pituitary secretion (TSH) weakens, the secretion of pituitary TSH increases, and the TSH level in the blood increases, causing thyroid hypertrophy and hyperplasia.

In severe cases, retrosternal goiter may occur, with the enlarged thyroid gland partially or completely located below the level of the sternum. Since the enlarged thyroid gland compresses surrounding organs, it may cause difficulty breathing, swallowing discomfort, and superior vena cava compression syndrome. Therefore, once a retrosternal goiter is discovered, surgery should be performed immediately, even for asymptomatic patients, in order to avoid malignant transformation or complications of sudden increase in size due to bleeding.

Thyroid cyst refers to the presence of fluid in the thyroid gland. Generally speaking, thyroid cysts do not have any symptoms unless they are very large or there are bleeding symptoms inside. At this time, the patient will feel oppression, such as difficulty swallowing when eating, breathing difficulties, and hoarseness. Generally speaking, there will be no malignant cells, so patients do not need to worry too much.