The thyroid might be a small gland, but it has a big job when it comes to keeping our bodies running smoothly. It is shaped like a butterfly and is located in the lower front of the neck. The thyroid produces hormones that regulate how your body uses energy. These hormones—primarily T3 and T4—affect everything from your metabolism and heart rate to your mood and energy levels. Think of your thyroid as the body’s natural thermostat: it controls how “fast” or “slow” our organs and systems work, depending on what we need.

When the thyroid isn’t working properly, it can cause either hypothyroidism (when it’s underactive) or hyperthyroidism (when it’s overactive).

Hypothyroidism can make you feel sluggish, gain weight, or feel cold, while hyperthyroidism can lead to symptoms like feeling jittery, losing weight, or experiencing a racing heartbeat. Because the thyroid influences so many aspects of our body and mind, even a small imbalance can have a noticeable impact on daily life.