Lumps in the gland. Nodules may be single or multiple (multinodular goiter) and may be due to benign colloid accumulations or 10% of the time cancer. See a thyroidologist to get a fine needle aspiration of any nodules that look suspicious on ultrasound.
Multiple things. Most thyroid nodules are benign and it is never clear why they formed. In some cases, the nodules occur with thyroiditis, an inflammatory disease of the thyroid gland. In other cases the nodules are from thyroid cancer. Biopsies are performed because any nodule could be a cancer, it is not usually possible to tell one way or the other without a biopsy.
Yes. Thyroid nodules occur in up to 50% of the worlds population. Modern ultrasound equipment can detect very small nodules that were not detectable with older machines. Only about 5% of nodules are cancerous. Nodules tend to increase in frequency as one matures.
Very. Thyroid nodules are extremely among the general population, more so in women than men. About 80% of nodules are benign in women and about 70% are benign in men. But all nodules over 1cm should be evaluated by a specialist.
Very. Very common, more common in females than males. Majority are benign.
Incidence of nodules. Thyroid nodules are very common. 50% of 50 year olds have them. About 1/3 are discovered by the patient, 1/3 by a doctor, and the rest are incidental found on an imaging study of the head, neck, or chest.
Part of the gland. They will move upward with the rest of the gland when you swallow, and you can move them just as you can move your larynx and trachea once you know your way around your neck. Your physician can help you make the distinction from a lymph node or other mass.
Moveable nodules. Thyroid nodules do not move but can change or "wax and wane". They can grow during growth spurts, from inflammation or bleeding within. As these episodes resolve they can shrink down, form cysts or become heterogeneous (mixed cystic and solid).
Hmm. Other than surgery (which I am not necessarily recommending), generally speaking thyroid nodules do not go away. You should have an ultrasound and possibly a needle aspiration. An endocrinologist or head and neck surgeon would be able to help get you worked up.