Thyroid hormones are crucial for the regulation of various metabolic processes in the body. The two primary thyroid hormones are:

1. Triiodothyronine (T3): This hormone is more active and potent. It plays a key role in regulating the body's metabolism, heart rate, body temperature, and the development of the brain.
2. Thyroxine (T4): This hormone is less active than T3 and acts as a precursor to T3. The body converts T4 into T3 as needed. T4 is responsible for similar functions as T3 but is less potent.

These hormones are produced by the thyroid gland, a butterfly-shaped gland located in the neck. The production and release of thyroid hormones are regulated by the pituitary gland's thyroid-stimulating hormone (TSH). Proper functioning of the thyroid gland and the balance of these hormones are essential for maintaining a healthy metabolism, growth, and development.

Imbalances in thyroid hormone levels can lead to various health issues. Hypothyroidism, characterized by insufficient hormone production, can cause symptoms like fatigue, weight gain, and depression. Hyperthyroidism, where too much hormone is produced, can lead to weight loss, increased heart rate, and anxiety.

Maintaining a healthy lifestyle, including a balanced diet and regular check-ups, can help in the management and prevention of thyroid-related disorders.