What is the cause of the sunken posterior fontanelle?

A baby is one of the most important members of a happy family. Every year, many babies die or the chance of a baby being born safely is not very high. Of course, with the improvement of medical standards, babies face various physical examinations as soon as they are born, which, to some extent, greatly increases the chances of babies growing up healthily. But there will always be various emergencies, and this will also manifest itself through some symptoms of the baby, such as a sunken posterior fontanelle. So what is going on with a sunken posterior fontanelle in a baby?

Fontanelle (xìn mén) refers to the bone gap formed by the loose connection of the skull bones of infants and young children. There are anterior fontanelle and posterior fontanelle. The anterior fontanelle[1] is located on the front vertex and is diamond-shaped. It closes approximately 12 to 18 months after birth. The posterior fontanelle is located above the occipital bone and is triangular in shape. It closes approximately 2 to 4 months after birth. The "skylight" or "fontanelle" that people often refer to mainly refers to the anterior fontanelle.

Posterior fontanelle

The posterior fontanelle is located at the back of the baby's head, at the intersection of the suture between the occipital bone and the two parietal bones. It is small and sometimes even difficult to feel. The posterior fontanelle is almost closed when the baby is born, or can only accommodate the tip of a finger, and closes about 2-4 months after birth.

Although the baby's fontanelle is not big, it is an important window reflecting the baby's physical health. By observing this small window when the baby is less than 1 year old, many diseases can be detected early, allowing the baby to be diagnosed and treated early. Therefore, mothers should know more about the normal development process of the baby's fontanelle and the abnormal phenomena that are prone to occur.

In this case, consider whether it is dehydration caused by a cold or fever: If the baby is in good spirits, has a good appetite and sleeps well, there are generally no other problems. If there are other discomforts, you need to go to the hospital for timely diagnosis to see if there is dehydration or symptoms caused by congenital brain maldevelopment.

A baby in a small family is not easy to come by, especially for the mother. The birth of a baby is the birth of a small life and also the rebirth of the mother. Moreover, the baby has just come into this strange world and has poor resistance to the outside world. When a baby is not adapted to the external environment, the body will show some symptoms, such as the sunken posterior fontanelle mentioned above.