The thyroid is an important part of your endocrine system, and one that influences nearly all of your body's metabolic processes. Thyroid diseases range from minor concerns that do not require treatment to life-threatening conditions including cancer, hyperthyroidism, and hypothyroidism. Fortunately, most thyroid problems are treatable or can be managed under a physician's care.* Depending on whether you suffer from hypo- or hyperthyroidism, the symptoms can vary significantly.