Haircare 101: Intro to How Hair Works

Haircare 101: Intro to How Hair Works

Our hair is important. Like, really important.

From a purely practical standpoint, hair insulates us and helps us regulate our body temperature. From a cultural standpoint, it can do everything from signify our identities, beliefs and affiliations, to help us attract a mate.

Most importantly, how we feel about our hair can influence our entire self-image. Those of us who have ever experienced a bad hair day or at-home color disaster can likely relate to not wanting to leave the house without our emotional support beanie.

The secret is that healthy hair is beautiful hair. This is why every hair model in every product advertisement is shown with hair that meets largely the same criteria. Cascades of voluminous, frizz-free, soft-looking strands, that shine so bright you’d probably want to wear shades if you were planning on looking directly at them. Regardless of hair type or texture, these are the hallmarks of healthy hair: volume, moisture level, and shine.

That being said, your hair is as unique as your fingerprint. In order to ensure optimal health, you’ll want to get really familiar with your hair’s unique characteristics and needs.

Getting to know your hair on a very intimate level will not only help you keep it healthy, it will also help strengthen your relationship with your stylist. By developing a deeper understanding of your hair’s preferences and needs, you will be able to communicate more effectively with your stylist. This is good for you, your stylist and of course, your hair.

Without further ado, let’s dive in and learn the fundamentals of hair ownership.


Part 1: What Hair Is: Structure & Lifecycle

While your hair may look and feel different depending on where it’s growing on your body, every single strand of hair is made of up of the same basic parts. There is the hair follicle, which grows below the skin and the shaft, which grows on top of the skin.

The hair follicle sits on top of a special gland that produces the oils that nourish the follicle and surrounding skin tissue. When new cells in the hair follicle multiply, they push old cell cells out. These old, dead cells harden and combine with a protein called keratin to form the hair shaft (or the part that you see).

This phase of the hair lifecycle—the anagen phase— is when hair is actively growing. After this phase, hair will pass into a resting (or catagen) phase for roughly two weeks before transitioning fully into the final phase of growth. The telogen phase is when a strand of hair is fully mature and is typically shed.

Most of us lose roughly 25-100 hairs in the telogen phase every single day. Believe it or not, this is perfectly normal and healthy and allows for new hair growth. Speaking of, while individual growth rates vary depending on a lot of factors, the average rate of hair growth is about .3-.4mm per day or roughly six inches per year.

This is why root touch ups are recommended by colorists every 4-6 weeks. Around this time, the average head of hair would have grown a little more than a half an inch and a difference in color would be noticeable. See? it’s all coming together now.

Part 2: Understanding YOUR Hair

While there may be a law of averages when it comes to growth and shedding rates, no two heads of hair are exactly alike. Believe it or not, every hair on your sweet head is absolutely unique to you.

While a full microscopic breakdown of the exact protein, mineral and lipid ratios may be more than we need (or want) to dive into here, there are some fundamentals that can be helpful to learn, in order to better understand your hair’s unique personality. Specifically, knowing your density, texture, type, and porosity levels are the key components in understanding how to best care for your hair.

Density is probably the most misunderstood characteristic of hair. How many times have we either heard or said, “Oh my hair is super thick/thin! I have a TON of/No hair!”. This is actually confusing texture with density. Texture refers to the characteristic of an individual hair strand, density refers to how many strands of hair that you have on your head. You can have either high, average or low density, and believe it or not, it mostly depends on your natural hair color.

Average Density by Color

Blondes: 130,000

Redheads: 80,000


Texture, as we said earlier, refers to the appearance—specifically thickness— of each individual strand of hair. Hair can be fine (small in diameter), medium, or coarse (large diameter). The easiest way to determine your hair’s texture is to pluck out a strand and roll it between your fingers. If you can barely feel it, you have fine hair. If you can feel it, but not necessarily notice it too much, you likely have medium texture. If your hair simply will not be ignored—congratulations, you have coarse hair.

Type refers mainly to your curl pattern (or last thereof). While many people believe that your hair type is a broad umbrella term that encompasses all of your hairs’ characteristics, your hair type really refers to how much bend each strand has. There are different classifications of hair type, and they each have their own subcategories*.


Basic Hair Types

Type 1: Straight

Type 2: Wavy

Type 3: Curly

Type 4: Very tightly coiled or “kinky”.

The subcategories for each of the hair types are determined by combining your hairs’ type with it’s texture, density and porosity levels, to create a complete profile. Interestingly, your hair type can be different in different sections of your hair.

Porosity level refers to how your hair retains moisture. Unless you have curly hair, you may not have even heard of this term, but it is a good one to know, regardless of your hair type. Testing your hair’s porosity is easy (and fun—in an amateur science experiment kind of way) and can be done at home in about five minutes.

How to test your hair’s porosity level

Step 1. Get a clear glass cup and fill it with 6-8 oz of water.

Step 2. Pluck out a strand of your hair.

Step 3. Drop the strand of hair into the cup.

Step 4. Wait 3-5 minutes

If your hair is floating at the top of the water level, you have high porosity hair. If the strand of hair sunk to the bottom, you have low porosity hair. If it’s floating around somewhere in the middle, you have medium porosity hair.

Your porosity level comes in handy when determining how much moisture and protein your hair needs, so it’s a great thing to discuss with your stylist.


Part 3: Things that Effect Your Hair

While your hair’s natural characteristics provide the foundation, there are a number of outside factors that can impact its overall health. Your hair is basically a barometer of your overall health. The better care you take of yourself, the better your hair will look. The most common factors that contribute to this are diet/lifestyle, scalp health, age, and treatment.

Diet & Lifestyle

Believe it or not, the  old adage is true: we are, in fact, what we eat. Every seven to 10 years, all of the cells in our bodes are replaced with new ones. While there are a lot of really interesting philosophical roads we could go down with this idea, we will stick with the fact that this includes the cells that make up your hair.

What you eat largely determines what your cells are made of, which makes your diet a major factor in your hair’s baseline health. Eating lots of leafy greens and veggies along with other foods high in Zinc, Chromium, B3 & B7 and Niacin can help keep things growing smoothly (and with lots of shine!)

Scalp Health

This one is really, really important and often neglected. Most people don’t even think about their scalp’s health until it has taken a turn for the worse. If you think of your hair like a garden, your scalp is a lot like the soil that your garden grows in. If there is something wrong with the soil, nothing can grow properly, which is why regular scalp care is an important part of any haircare regimen.

Product buildup is a common culprit that most people dont consider when it comes to addressing scalp health. Using the right products for your hair is key, but every so often you want to go through with a good clarifying shampoo and clear out anything that may be left behind, as old leftover product on the scalp can lead to dandruff.

If youve been taking regular care of your scalp, have ruled out product buildup as a possibility and are still having scalp issues, it may be time to talk to your stylist or doctor. An itchy or scaly scalp can be an indicator of one of the more serious scalp ailments like psoriasis, folliculitis, or seborrhiac dermatitis.


With great wisdom comes a change in hair color, density, porosity and sometimes even type and texture. As we age, our hair strands become finer and have less and less pigment. The loss of pigment molecules introduces more porosity into each strand, which can make hair feel drier, as it has a harder time retaining moisture. While making healthy diet and lifestyle choices can make a big impact, the effects of aging on hair are inevitable and will require a change in care.

Hair Treatment

How we treat our hair is going to have a big impact on how healthy it is. There are two main aspects to hair treatment: day-to-day care and styling regimen and chemical processes.

A healthy day-to-day care and styling practice starts with a deep understanding of your hair’s unique needs. Hair that is low in density and high in porosity with a tight curl pattern will likely need products designed to deliver volume, high levels of moisture, and frizz-control. This care and styling “prescription” will look very different for someone with a different hair type or texture.

It doesn’t start and stop with hair type. All hair reacts differently to changes in environment. So, no matter how perfect your combination of care and styling products performs in the heat of the summer, they will likely be less effective in the drier, colder, winter months.

Hair that has been chemically processed (I.e. colored, permed or relaxed) will have very different needs than virgin hair. Depending on the process and how often it’s performed, there may be additional treatments needed to replenish protein levels, or moisture or both. You will also want to take good care of your fresh color, curls or freshly straightened locks by using maintenance products specially designed to support these processes at home.

It can be a bit overwhelming to navigate the vast landscape of different products available and find the right combination for your specific hair. By learning a little bit more about how hair works, you are taking a very important first step in a well-informed healthy hair journey. Just take it slow, continue to educate yourself, and remember that you can always get feedback from your stylist.