6-month-old babies always shaking their heads may be related to overdressing, skin eczema, otitis media and so on. 1. Wearing too thick clothes: If parents give their 6-month-old baby too thick clothes, it will make the baby feel hot. As babies are too young to express clearly, they may indicate that they are too hot by shaking their heads. 2. Skin eczema: When your 6-month-old baby develops skin eczema on the neck or head, it will make your baby feel itchy on the head and neck. Coupled with the fact that babies do not have the means to scratch on their own, babies may rub the itch by shaking their heads. 3. Otitis Media: When babies suffer from otitis media, they may feel pain in their ears. Since 6-month-old babies are unable to express themselves, they may appear to shake their heads all the time. When 6-month-old babies appear to shake their heads all the time, parents should take their babies to seek medical treatment in time to clarify the cause and under the guidance of professional doctors.