What Are the Four Types of Hair?

The four hair types are type 1 straight, type 2 wavy, type 3 curly, and type 4 tight curls.

The four types of hair are straight, wavy, curly, and tight curls. Learn about how hair types and texture can be affected by several factors, and how to care for each hair type.

Hair type and texture are determined by several factors including genetics. Straight hair is one of the most common hair types across the world. Each person has a unique hair type and texture.

Hair texture refers to the thickness of each hair strand. Thickness of hair should not be confused with density of hair, which is the number of hairs on one's head. The basic types of hair texture are fine, medium, and coarse. Fine hair is fragile and is the thinnest of the three types of hair textures, coarse is the thickest, and medium falls in between the two.

There are four main types of hair: Type 1 - straight, Type 2 - wavy, Type 3 - curly, and Type 4 - tightly curled. Each type of hair may have any of the 3 textures. The hair type and texture can be further broken down into a, b, and c based on the hair's curl pattern, density, porosity, width, and length. For example, someone with loose curls would be Type 3a and someone with bouncy curls would be Type 3b.

Here is a simple guide on hair types that explains each one:

• Type 1 is straight hair that doesn't curl. This hair type also has the most sheen, is the most resilient, and is hard to damage. It is also immensely difficult to curl this type of hair because the scalp sebum spreads easily from the scalp to the ends, making it the most oily type of hair and difficult to style.
  • 1a - Stick straight
  • 1b - Straight with more volume
  • 1c - Straight with body wave and a couple of visible S-waves, usually the neck or temples
• Type 2 is wavy hair that is in between straight and curly. The sheen is in between wavy and curly. Wavy hair is also more likely to become frizzy than straight hair. Certain types of wavy hair are easy to style, whereas others are more resistant to styling.
  • 2a - Loose, stretched S-waves
  • 2b - Shorter, more distinct S-waves
  • 2c - Distinct S-waves with some spiral curls
• Type 3 is curly hair that looks like the letter “S” or “Z.” This hair type is usually voluminous. Curly hair types are highly climate-dependent and can become frizzy and get damaged easily. Proper care is required to maintain healthy, well-defined curls.
  • 3a - Big, loose spiral curls
  • 3b - Bouncy ringlets
  • 3c - Tight corkscrew curls
• Type 4 is the hair that is coiled very tightly. It is often fragile with a very high density. This type of hair shrinks when wet because it has fewer cuticle layers than other hair types. It is more susceptible to damage than other hair types.
  • 4a - Tightly coiled S-curls
  • 4b - Tightly coiled, Z-pattern curls
  • 4c - Mostly Z-patterned, tightly kinked, and less defined curls

Your genes determine your hair type and texture, but the environment can also have an impact on your hair. Hair size and shape are established in the hair follicle. Studies suggest that symmetric hair follicles produce round hair fibers that grow straight. Asymmetry in the hair follicle region where hair cells grow and proliferate makes the hair fiber elliptical or oval-shaped, which grows out curly. Genetic traits determine this process.

• Genetics of hair types: Research shows that hair type and texture are inherited. There is also an “additive” trait contributing to hair type and texture. This means the amount of curl in the hair depends on how many curly hair gene variations are inherited. Hence, two curly-haired parents may not always have curly-haired children because many different genes are involved. Curly-haired parents can also carry straight hair genes, which they may pass on. Genes can also interact with each other to determine hair texture. This is the reason why in a family, different people may have different types of hair.
• Environment: Genes aren't the only factor affecting hair type. The environment can also have a big impact on hair, especially the texture. Humidity can make the hair frizzy or curly, whereas cold winter air can make hair dry and frizzy. Hair texture also changes with age. Hair becomes grey, thinner, rougher, finer, and dry. The oil glands in the scalp shrink with age. Hormones and certain medications also can temporarily or permanently change your hair's characteristics. How you treat and style your hair can change its texture. Bleaching, hair coloring, using styling tools, straightening, and perming can change hair texture.

Your hair type is encoded in your DNA and it is not possible to change the genetic nature of hair. However, several at-home and salon treatments can help straighten or curl the hair. Some of the methods are long-lasting, whereas others are temporary.

The following are the long-lasting treatments to change hair types:

• Professional permanent perming or straightening: This is a chemical process that permanently alters the hair. It changes the protein bonds in the hair. The results can last for several years depending on the chemicals used. The new hair that grows would be of the person's original hair type.
• At-home treatments: Several chemical kits can be used to straighten or curl the hair. Some products may provide results that last a few months, whereas others may last longer.
• Semi-permanent hair straightening: Keratin hair treatment, Brazilian blowouts and other semi-permanent hair straightening treatments can help straighten hair. They are usually done at salons. The results last three to five months.

The results typically last until the next hair wash. Temporary methods include:

• Blow drying: Blow drying is done by blasting hot or cold air on the hair using a round or flat brush to curl or straighten hair.
• Using hair care products: Shampoos, conditioners, leave-in conditioning products, hair serums, and hairsprays are used to coat the hair strands, reduce frizz and curls, and improve hydration.
• Applying essential oils: Using natural oils such as coconut oil, almond oil, argan oil, or a combination of oils can help improve hair texture. They can be applied all over the scalp and hair and washed after 30 to 60 minutes with shampoo and conditioner. This may be done multiple times a week.
• Hairstyling tools: Hairstyling tools such as hair straighteners or curlers use heated plates powered by electricity that can quickly straighten or curl hair. These are easy and quick to use.

You will need to follow a hair care regimen based on your hair type and texture, and your hairstyle. Choose hair care products that suit your hair type. For instance, fine straight hair can often look limp, and using a dry shampoo can make it look more voluminous. Coarse hair type can look softer and less frizzy with deep conditioning creams and serums.

Although the term, “coarse” can mean “rough,” coarse hair is distinct from rough hair. Coarse hair refers to the thickness of a hair strand, while rough hair texture results from dryness and damage to the hair. Dryness can be caused due to too much shampooing, the use of styling tools such as curling or flat irons, dryers, and rollers, or certain health conditions. Rough hair texture can improve with the use of appropriate moisturizing shampoos, conditioners, and oils.

What is Type 4 hair called?

Curly hair with very tight coils is called Type 4 hair. Type 4 hair can be of fine, medium, or coarse texture, but is most often coarse and voluminous. This type of hair is more sensitive to damage from heat and styling products than other types of hair.

How to identify my hair type

You can identify your hair type by washing your hair and letting it dry without using a conditioner or serum, and observing how it looks. Another way is to comb your hair and remove a few strands of hair that come out in the comb. Place the strands on a white paper and see whether they stay straight or curl up.

What is the most difficult hair type?

Each hair type has unique characteristics that require appropriate management. When you look at curly hair vs wavy hair, curly hair is more difficult to manage because it is denser and more fragile than wavy hair. Type 3 and Type 4 hair are more prone to dryness and tangles and will require gentle handling to prevent damage, However, wavy hair is more likely to get frizzy, especially in humid weather.

Straight hair is the least susceptible to damage, easy to manage and grow out, but most difficult to style. The natural scalp oil (sebum) can spread easily to the hair ends making the hair look limp and flat. Straight hair usually needs washing and styling more often, unlike wavy or curly hair which retains its style for a longer period.