Greasy hair is a hair condition which is common in humans, one of four main types of hair conditioning— normal, greasy, dry and greasy dry.[1] It is primarily caused by build-up of the natural secretion from the sebaceous glands in the scalp and is characterised by the continuous development of natural grease on the scalp.[2] A chronic condition of greasy hair may often accompany chronic greasy skin conditions on the face and body and oily skin and acne.[3] Excessive carbohydrate, fat and starch consumption can increase the likelihood of developing greasy hair and also poor personal hygiene and not washing the hair for a long duration will lead to a buildup of sebum in the hair follicles.[3] [4] Hair conditioners can decrease the likelihood of developing greasy hair after shampooing.[5] Some cosmetics companies produce shampoos and conditioners specifically to deal with greasy hair and for oily or dry hair problems.[6] Massaging the scalp and exposure to the sun can reduce the problem of greasy hair.[7]
In combination with hairstyles such as pompadours and undercuts, a greased back wet hair look is considered desirable. Hair gels and waxes known as pomades are applied to form the hair and give it a greasy texture.