Summary
Highlights
The thyroid, a small organ in the neck, acts as an operations manager for the body, using hormones to deliver messages to every cell and ensure proper functioning. It consists of lobules containing follicles that store hormones like thyroxine (T4) and triiodothyronine (T3).
Thyroid hormones instruct cells on consuming oxygen and nutrients, maintaining the body's metabolism. They make the heart pump efficiently and accelerate nutrient breakdown, enabling cells to use energy, grow, and reproduce. When more energy is needed, the thyroid increases metabolism by releasing more hormones.
The pituitary gland in the brain controls the thyroid by sensing hormone levels and issuing instructions via thyroid-stimulating hormone (TSH). However, this system can falter due to diseases, growths, or chemical imbalances. This can lead to hyperthyroidism (too many hormones), causing rapid heart rate, hunger, weight loss, anxiety, and difficulty sleeping.
The opposite problem is hypothyroidism (too few hormones), which results in cells becoming listless and metabolism slowing down. Symptoms include weight gain, sluggishness, cold sensitivity, swollen joints, and low mood. Fortunately, medical treatments can help regulate thyroid activity and restore a steady metabolic rate.