What should I do if I have a thyroid cyst? First, we need to understand what a thyroid cyst is. A thyroid cyst refers to a fluid-filled sac found in the thyroid gland. Generally, patients with thyroid cysts do not show any clinical symptoms in the early stages. Some discover a lump accidentally, usually without systemic symptoms. Individual patients may exhibit symptoms such as hyperthyroidism, and some with a longer disease course can also experience hypothyroidism, such as fatigue, poor appetite, constipation, and edema. Therefore, when diagnosed with a thyroid cyst, it is crucial to determine whether the cyst is benign or malignant and whether it affects thyroid function. If it does impact function, symptomatic treatment is necessary. Of course, most thyroid cysts are benign and can be monitored over time.