What are hot and cold nodules?
Thyroid nodules do not function like normal thyroid tissue. A thyroid image (scan) done with a radioactive chemical shows the size, shape, and function of the gland and of thyroid nodules. A nodule that takes up more of the radioactive material than the rest of the gland is called a hot nodule. A nodule that takes up less radioactive material is a cold nodule. Hot nodules are seldom cancerous, but less than 10% of all nodules are hot. Cold nodules may or may not be cancerous. All lumps in your neck should be checked by your doctor.