Whether thyroid nodules cause headache and dizziness depends on the size of the nodule and the specific nature of the nodule. 1. If the nodule is small and does not cause local neurovascular compression, ultrasound or CT examination reveals that the nodule has clear borders, uniform echogenicity, no obvious blood flow signal and malignant tumor signs such as aspect ratio greater than 1. 2. The prognosis is relatively good. 2. If the thyroid nodule is large and causes obvious compression of blood vessels in the neck, it may cause ischemia and hypoxia in the head due to insufficient blood supply to the brain, and the patient may have headache and dizziness. 3. If the thyroid nodule is considered to be malignant, the tumor cells may be invaded into the skull by blood vessels and lymph vessels, thus causing dizziness and headache. Therefore, early surgical treatment is needed to avoid serious complications.