The thyroid is a small, butterfly-shaped gland located in the front of the neck. It produces hormones, primarily thyroxine (T4) and triiodothyronine (T3), which play a crucial role in regulating the body's metabolism, energy levels, and overall growth and development. These hormones influence how the body uses energy, affecting everything from heart rate to weight management. Thyroid function is controlled by the pituitary gland, which releases thyroid-stimulating hormone (TSH) to signal the thyroid to produce T4 and T3. Proper thyroid function is essential for maintaining a healthy balance in the body, and any dysfunction can lead to conditions such as hypothyroidism or hyperthyroidism.