Hashimoto's Thyroiditis is an autoimmune disorder where the body's immune system mistakenly attacks the thyroid gland. This small butterfly-shaped gland, located in the neck, produces hormones that regulate metabolism, energy levels, and overall health. As the immune system damages the thyroid, it can lead to hypothyroidism, a condition where the gland doesn't produce enough hormones, causing symptoms like fatigue, weight gain, and depression. People with Hashimoto's Thyroiditis may experience fluctuations in their thyroid hormone levels, leading to periods of both high and low hormone production. Diagnosis typically involves blood tests to check hormone levels and the presence of specific antibodies. Treatment often includes hormone replacement therapy to help manage symptoms and restore normal thyroid function.