This chapter discusses common and rare abnormalities in the head and neck region, ranging from torticollis to swelling that may not initially appear clear in nature. It also covers swelling in the mucous membrane of the mouth. Upper respiratory infections, throat, nose, and ear infections are the most common causes of swelling in the head and neck region during childhood. The lymphatic tissue in this area is rich, and infections often lead to lymph node enlargement. Swollen cervical lymph nodes can be caused by various infections, including atypical mycobacteria, Epstein-Barr virus (mononucleosis infectiousa), toxoplasmosis, and Bartonella henselae (cat scratch disease). A lymph node is considered enlarged if it is larger than 1 cm; for children under 12 years old, lymph nodes smaller than 1 cm are considered normal. Congenital abnormalities of the head and neck can be present at birth or develop later, such as median and lateral cervical cysts, dermoid cysts, and hygromas. These conditions, along with rare malignancies, present a wide range of differential diagnostic possibilities. More than half of children may have palpable lymph nodes in the neck without an infectious cause. Lymphadenopathy caused by infections is a common finding in childhood, typically occurring between the first and fourth years of life. The incidence of median cervical cysts is about 1 per 2,000 children, while lateral cervical cysts are rarer and more common in older children. Hygromas and 'plunging' ranulas are very rare. Approximately 1 in 6,000 children presents with a malignant swelling in the neck, with Hodgkin's disease being the most common in children over 10 years old. Other rare forms include rhabdomyosarcoma, neuroblastoma, and teratoma. The age of the child is crucial for diagnosing neck swelling. Newborns may have a swelling due to a hematoma following difficult childbirth. If the swelling is fixed to the sternocleidomastoid muscle, it could be the first signs of torticollis, which usually appears during the first few months. Hygromas and hemangiomas are often present at birth and grow during the first year. Dermoid cysts, median, and lateral cervical cysts are congenital conditions that usually appear later. Lymph nodes smaller than 1 cm are common in childhood, except for those with pathological findings in newborns. The duration and growth of the swelling are important parameters for diagnosis. A swelling lasting less than four weeks is usually caused by bacterial or viral lymphadenopathy, mycobacterial infections, or toxoplasmosis. Infections by atypical mycobacteria or Mycobacterium tuberculosis often have a longer course. Pain is a characteristic of bacterial or viral lymphadenopathy, while infections by mycobacteria rarely cause pain.This chapter discusses common and rare abnormalities in the head and neck region, ranging from torticollis to swelling that may not initially appear clear in nature. It also covers swelling in the mucous membrane of the mouth. Upper respiratory infections, throat, nose, and ear infections are the most common causes of swelling in the head and neck region during childhood. The lymphatic tissue in this area is rich, and infections often lead to lymph node enlargement. Swollen cervical lymph nodes can be caused by various infections, including atypical mycobacteria, Epstein-Barr virus (mononucleosis infectiousa), toxoplasmosis, and Bartonella henselae (cat scratch disease). A lymph node is considered enlarged if it is larger than 1 cm; for children under 12 years old, lymph nodes smaller than 1 cm are considered normal. Congenital abnormalities of the head and neck can be present at birth or develop later, such as median and lateral cervical cysts, dermoid cysts, and hygromas. These conditions, along with rare malignancies, present a wide range of differential diagnostic possibilities. More than half of children may have palpable lymph nodes in the neck without an infectious cause. Lymphadenopathy caused by infections is a common finding in childhood, typically occurring between the first and fourth years of life. The incidence of median cervical cysts is about 1 per 2,000 children, while lateral cervical cysts are rarer and more common in older children. Hygromas and 'plunging' ranulas are very rare. Approximately 1 in 6,000 children presents with a malignant swelling in the neck, with Hodgkin's disease being the most common in children over 10 years old. Other rare forms include rhabdomyosarcoma, neuroblastoma, and teratoma. The age of the child is crucial for diagnosing neck swelling. Newborns may have a swelling due to a hematoma following difficult childbirth. If the swelling is fixed to the sternocleidomastoid muscle, it could be the first signs of torticollis, which usually appears during the first few months. Hygromas and hemangiomas are often present at birth and grow during the first year. Dermoid cysts, median, and lateral cervical cysts are congenital conditions that usually appear later. Lymph nodes smaller than 1 cm are common in childhood, except for those with pathological findings in newborns. The duration and growth of the swelling are important parameters for diagnosis. A swelling lasting less than four weeks is usually caused by bacterial or viral lymphadenopathy, mycobacterial infections, or toxoplasmosis. Infections by atypical mycobacteria or Mycobacterium tuberculosis often have a longer course. Pain is a characteristic of bacterial or viral lymphadenopathy, while infections by mycobacteria rarely cause pain.