The thyroid, a small butterfly-shaped gland at the base of the neck, regulates the body's metabolism. A thyroid nodule is a lump within the thyroid. It can be solid or filled with fluid, according to the Mayo Clinic. There are many reasons for developing a thyroid nodule, 95 percent of which are benign, according to EndocrineWeb. Nevertheless, a doctor should be consulted if a nodule is found. The treatment for a thyroid nodule depends on the cause.
Prevalence
As is true for many thyroid disorders, women are more likely to develop thyroid nodules than men, reports the Mayo Clinic. The incidence increases with age, with one or more nodules present in about half of 50-year-olds and 70 percent of people who have reached aged 70, according to EndocrineWeb and the Mayo Clinic.
Types
There are several types of thyroid nodules. The most common is a colloid nodule, a benign overgrowth contained within the thyroid, explains the Mayo Clinic. Another benign type is follicular adenoma. A cyst is a nodule that is filled with fluid, although complex cysts, which have a greater chance of being cancerous, are both fluid and solid.
Nodules occasionally develop if the thyroid is constantly swollen, which has many causes, including viral infection. A hyperfunctioning thyroid nodule produces thyroid hormones without instruction from the pituitary gland, which is what occurs normally. It may be caused by a genetic defect. Finally, although uncommon, the nodule may be malignant.
Symptoms
Most thyroid nodules do not cause symptoms and are discovered accidentally or during a routine checkup by a doctor, reports EndocrineWeb. If the nodule is large or many are present, a person may see visible swelling or experience difficulty breathing or swallowing, according to the Mayo Clinic. If the nodule secretes thyroxine, which is normally produced by the thyroid gland, a person may feel jumpy, have a rapid heartbeat or suddenly lose weight.
Risk Factors
Being female or older increases the chance for a thyroid nodule, reports the Mayo Clinic. People with family members who have had a thyroid nodule also have a higher risk. Exposure to radiation, either as radiotherapy or from atomic testing or nuclear power plants, increases the likelihood of developing thyroid nodules.
Treatment
Many strategies are used to treated thyroid nodules, depending on the cause, according to the Mayo Clinic. If the nodule is benign, which is established by a biopsy, and remains the same size, simply checking on it periodically with a physical exam and hormone blood test may be all that is necessary.
If the thyroid is malignant, it must be removed, along with the tissue around it. Surgery also may be performed if the nodule is so large that a person has a hard time swallowing or breathing.
