Thyroid nodules are abnormal growths or lumps that occur in the thyroid gland. Most thyroid nodules are not cancerous (are benign) and usually do not create problems. Many do not require treatment. Only about 5% of nodules are cancerous. They must be excised after a surgrical procedure. In rarely cases thyroid nodules can cause thyroid problems. When a node is producing too much thyroid hormone (hyperthyroidism), the thyroid gland is overactive.
Thyroid Nodules Causes
The exact cause of thyroid nodules is yet unknown. It is known however that those exposed to radiation have higher risk of developing thyroid nodules. Exposure to environmental radiation or radiation therapy prior to the head, neck or chest (especially during childhood) increases risk of thyroid nodules. Scientists estimated that thyroid nodules are transmitted genetically. So if a parent had thyroid nodules, children have a higher risk of developing thyroid nodules. If another disorder og the thyroid gland is associated (goiter for example) the risk of thyroid nodules is higher.
Thyroid Nodules Symptoms
Most nodules are asymptomatic and go unnoticed. Thyroid nodules are often discovered during a routine examination or investigations such as computed tomography or ultrasound performed for other health problems. If your thyroid nodules are large enaugh they can be palpated or you can notice an increase in volume of the neck.
In rare cases you may feel:
- Pain or feeling of fullness in the neck
- Difficulty in swallowing
- Difficulty in breathing
- Nervousness, tachycardia, sweating, weight loss or other symptoms of hyperthyroidism (excess thyroid hormone)
- Fatigue or depression, memory problems, constipation, dry skin, feeling cold or other symptoms of thyroid hormones deficiency.
Other conditions that cause similar symptoms are hyperthyroidism and thyroiditis.
Most thyroid nodules are benign and are not causing any problems. Are often difficult to observe as thyroid nodules are usually very small. Many people have thyroid nodules that are not discovered or treated. There are three types of thyroid nodules: solid nodules, filled with fluid (cystic) and partially cystic nodules. Solitary or multiple thyroid nodules may be present (multinodular goiter). Also, solid and cystic nodules can coexist. Solid nodules often grow more slowly. Rarely cystic nodules can bleed, which may lead to a sudden increase in volume and causes pain. Thyroid nodules usually do not interfere with the function of the gland.
However, sometimes a benign nodule can cause:
- Hyperthyroidism, when one or more nodules produce thyroid hormones, hyperthyroidism is treated with antithyroid medication, possibly radioactive iodine and rarely surgery, hyperthyroidism caused by thyroid nodules is rare (occurs in less than 1 in 100 people with thyroid nodules)
- Difficulty breathing or swallowing, when one or more nodules press on the tracheea sau esophagus, these nodules need surgical excision. Only about 5% of nodules are malignant. Thyroid cancer is usually discovered and treated early, so most people evolve favorably.
Thyroid Nodules Risk Factors
Possible risk factors:
- Age, thyroid nodules are more common in older people
- Female sex
- Exposure to radiation: environmental radiation or previous radiotherapy to the neck, head or chest (especially during childhood) increases the risk of thyroid nodules
- Iodine deficiency, which can lead to goiter with or without nodules
- Hashimoto thyroiditis, that causes underactive thyroid (hypothyroidism);
- One or both parents with thyroid nodules.
Thyroid nodules are more likely to be malignant if:
- The patient was exposed to radiation, although rare, thyroid cancer can occur after 20 years of radiation or exposure to environmental radiation.
- Family members with cancer of the endocrine glands, including thyroid.
- Thyroid nodules that occur in people under 20 or over 60 years.
- Male sex.
- Thyroid Nodules increase rapidly (weeks or months), however just because a thyroid nodule grew in volume it does not mean it is necessarily malignant.
- Thyroid nodules that occur during pregnancy.
- Graves Basedow disease is present.
- Hashimoto’s thyroiditis in history.
You should see a specialist if you notice any of the following thyroid nodules symptoms:
- Any swelling in the neck that does not disappear in two weeks;
- Hoarseness in the absence of cold or throat infection that persists more than one month
- Difficulty in swallowing;
- Symptoms of thyroid dysfunction (fatigue, weakness or sudden weight loss).
In the case of surgical extirpation of a portion of the thyroid gland due to a benign node, regular medical checks for evidence of possible changes will be needed.
Also see: Thyroid Nodules Diagnosis