Goiter refers to swelling of the thyroid gland that appears like a lump in the neck. The thyroid is a small butterfly shaped gland present in the neck. It produces thyroid hormones that help in the regulation of the body's metabolism. They also aid in smooth functioning of the brain, heart, digestive system, and muscles.

The main causes of goiter are overactive thyroid, underactive thyroid, or any other underlying disease. It may or may not be associated with abnormal thyroid hormone level.

The main symptom is enlargement of the throat, ranging from a small lump to a huge mass. It can be seen in people from any age group starting from new born baby to elderly. Pregnant or menopausal women, people older than 40, and people who have an autoimmune disease or a family history of goiter have a higher risk of developing goiter. 

The treatment of goiter depends on the cause, symptoms, and complications associated with the disease. It can be successfully managed by medications, hormone therapy, and surgery.