Hair care is an overall term for parts of hygiene and cosmetology involving the hair on the human head.

Care of the hair and the scalp skin are sometimes considered separate, but are often intertwined because hair grows from underneath the skin. The living part of hair is the hair follicle which contains the hair root, the sebaceous gland, the vessel for delivering nutrients (via the blood), and other parts. Hair itself is very living; however, much can be done to manage hair and ensure that the outer surface of hair, the cuticle, will remain intact and continue to protect the inner parts of the hair cell (the cortex and the medulla).

Hair care will differ according to one's hair type and according to various processes that can be applied to hair. All hair is not the same; indeed, hair is a manifestation of human diversity.

When hair behaves in an unusual way, or a scalp skin disorder arises, it is often necessary to visit not only a qualified physician, but sometimes a dermatologist, or a trichologist. Conditions that require this type of professional help include, but are not limited to, forms of alopecia, hair pulling/picking, hair that sticks straight out, black dots on the hair, and rashes or burns resulting from chemical processes.go on an all nutrition diet....

For many, hair care means a visit to a professional stylist. The discussion of hair is a major world industry, from the salon to products to advertising and even magazines on the subject. Indeed, the topic is displayed and discussed in various online discussion forums. Hair care can include hairdressing (or 'hair dressing'), where the hair is blown dry, combed and/or styled. Hair dressing may include perms, weaves, coloring, extensions, permanent relaxers, curling and any other form of styling or texturing.

Styling tools may include Hair irons (including flat and curling irons), hair dryers, Hairbrushes (both flat and round), hair rollers, diffusers and various types of scissors. Hair dressing might also include the use of product to add texture, shine, curl, volume or hold to a particular style.

In this article, 'Hair care' is taken to mean care of hair on the human head, but mention should be made of other services available in salons such as barber shops which include men's beard and skin care for the beard, and possibly also waxing services of other sites on the human body where hair may be removed. (Hair removal can also be done via laser applications, but often this is not offered in a salon and is conducted under physician care.) Hair dressing (and resulting care requirements) are in many ways more often associated with the female gender, but hair care and dressing is no longer just for females, if indeed it ever was. Many males benefit from improved care, especially considering that males also color (music industry, to cover gray) and enjoy alternative shapes and styles themselves.

Haircuts may also include services mentioned under hair dressing. Cutting hair often involves creating a specific shape and form, and maintaining such sculpture. Haircuts can also be used to define a hemline along the ends and edges of longer lengths and amongst longer lengths. Hair cutting may include shaving the head, in which case scalp skin care would be required. In some settings, hair cutting, creating forms and shapes are an expressive art form. Hair cutting often involves considerations of body proportions, hair density and hair type, face and head shape from all views (profile, 3/4 and 360 degree, from above and from below), overall bone structure, and pattern of how hair lies or falls.

Hair shapes and various lengths are often derived from concerns regarding personal expression and aesthetics (examples: dreadlocks, punk hair, the business haircut/style, very long hair), religion (for example, Pentecostal faith among others), social and cultural values. In short, hair is often a physical expression of one's sense of self, of a desire to present oneself to and amongst a community, of social status and roles, and of cultural values. Such expression often involves adding ornaments to the hair, or partial or full hair coverings (such as a Kippa, Hijab, or a Turban).

Hair care also includes hair washing. Scalp skin that is not cleansed regularly may become a prime breeding ground for bacteria, and scalp disorders may result. However, not all scalp disorders are a result of bacterial infections. Some arise inexplicably, and often only the symptoms can be treated for management of the condition (example: dandruff). There are also bacteria that can affect the hair itself, but in first world countries, this is much rarer. Head lice is probably the most common hair and scalp ailment world-wide, but can be rid of in time with great attention to detail, and studies show it is not necessarily associated with poor hygiene. (Indeed, even well-to-do households can experience head lice. More recent studies reveal that head lice actually thrive in clean hair.)

Hair washing as a term may be a bit misleading as what is really necessary is cleaning the surface of the scalp skin, the way the skin all over the body requires cleaning for good hygiene. Often hair is washed as part of a shower or bathing with a specialized soap called shampoo. Conditioner is recommended after rinsing out shampoo to replace moisture in the hair shaft, the cortex, as well as to protect the hair strands from breakage to moisten the hair and ease detangling and manageability.

Scalp hair grows, on average, at a rate of about half an inch per month, and shampoos or vitamins have not been shown to noticeably change this rate. Hair growth rate also depends upon what phase in the cycle of hair growth one is actually in; there are three phases. The speed of hair growth varies based upon genetics, gender, age, hormones, and may be reduced by nutrient deficiency (i.e., anorexia, anemia, zinc deficiency) and hormonal fluctuations (i.e., menopause, polycystic ovaries, thyroid disease).