This page explains the causes of thyroid nodules, how ultrasounds and biopsies are used to evaluate them, and why most thyroid nodules are benign and not dangerous.
Hearing that you have a thyroid nodule can feel scary.
The good news:
➡ Most thyroid nodules are harmless and not cancer.
This page explains what nodules are and what they usually mean.
A thyroid nodule is simply:
➡ A small lump or growth inside the thyroid gland.
Nodules are very common.
Many people have them and never even know.
Thyroid nodules are extremely common:
Up to 50–60% of adults may have small nodules
Many are found by accident
Most cause no symptoms
They are often discovered during:
A routine exam
An ultrasound
A scan done for another reason
Not all nodules are the same.
They can be:
Made of thyroid tissue
Filled with fluid
Part solid, part fluid
Nodules can also be described as:
Produce extra thyroid hormone
Can cause hyperthyroidism
Do not produce hormone
Most nodules fall into this category
Most nodules cause no symptoms at all.
But sometimes they can cause:
A lump you can feel in the neck
A sense of fullness
Trouble swallowing
Hoarseness
Pressure in the throat
If a nodule is “hot,” it may cause hyperthyroid symptoms.
This is the most common worry.
Here is the reassuring fact:
➡ Over 90–95% of thyroid nodules are NOT cancer.
Thyroid cancer is relatively rare, and most nodules are benign.
Doctors evaluate nodules in several steps.
Usually the first test is:
This shows whether the nodule is affecting thyroid function.
An ultrasound helps show:
Size
Shape
Solid vs fluid
Features that look suspicious or not
Ultrasound is painless and very helpful.
If a nodule looks concerning or is large enough, doctors may do:
➡ Fine Needle Aspiration Biopsy
This involves:
A tiny needle
Removing a few cells
Checking them under a microscope
It is quick, safe, and usually done in the office.
Doctors decide based on:
Size of the nodule
Ultrasound appearance
Growth over time
Family history
Symptoms
Small, simple nodules often do not need biopsy.
Biopsy results usually fall into categories like:
Benign (non-cancerous)
Suspicious
Indeterminate
Malignant (cancer)
Most come back benign.
Treatment depends on the type of nodule.
Often no treatment is needed.
Doctors may recommend:
Watching it over time
Repeat ultrasound checks
Monitoring for growth
Treatment may include:
Anti-thyroid medications
Radioactive iodine
Surgery
Thyroid cancer is usually:
Very treatable
Slow growing
Often curable with surgery
Some nodules:
Stay the same size
Grow slowly
Occasionally shrink
Rarely disappear completely
That’s why follow-up is important.
If you’re told you have a thyroid nodule, the typical steps are:
Check TSH
Do a thyroid ultrasound
Decide if biopsy is needed
Monitor over time if benign
Most people end up needing only simple monitoring.
Thyroid nodules are very common
Most cause no symptoms
Most are not cancer
Ultrasound helps guide decisions
Many nodules only need observation
The next page will cover: