Read the latest in Beauty News from our professional therapists at Complete Skin & Beauty.

Skin Science

Let's talk about Skin Science!

The skin is an important part of the Integumentary System; a system that is made up of your skin, hair, nails and sweat glands. This protective system is the body's outer covering or 'coat' and is there to keep you safe from harm.

Allow me to break down the different parts of the Integumentary System:

  • Your skin is the main part of this system, and is also the largest organ of our body. It is a barrier that keeps all the bad stuff out while locking all the good stuff in.
  • Hair and nails are the extra layers of protection, helping shield your skin and nerves from scratches and bumps.
  • Your sweat glands help you to stay cool when you are hot, and provide one form of expelling toxins through releasing sweat onto your skin.

Let's take a closer look at the skin. As the largest organ in your body, your skin is responsible for several roles and responsibilities. It varies in texture and thickness from one part of the body to the next. Although fascinating, it is an extremely complex organ divided into 3 important layers.

Let me simplify the layers of the skin...

If you imagine your skin as a big wall protecting your body from the outside, the wall will have 3 main layers. The Epidermis, the Dermis and the Hypodermis.

Epidermis (outer layer)

Think of the epidermis as the ‘roof of your house’ top layer of skin.

The epidermis is the outermost layer of your skin, acting as a protective shield.

It is made up of tough cells that are tightly packed together, like bricks in a wall. These cells work together to keep all the bad stuff out and all the good stuff in.

Dermis (middle layer)

Imagine the dermis as the strong walls of your house, it is the biggest layer of the skin, providing all the structure. It is the middle layer of the skin sandwich.

Think of the dermis as the main support system for your skin. It’s like the framework of a building, providing structure for the skin. Or like a busy city with important infrastructure needed for your skin to function properly.

This section of your skin holds a web-like structure of collagen and elastin, fibroblast cells, melanocyte cells, phagocytes (cells that fight bacteria) and capillaries. 

In summary, the dermis is the tough, supportive layer of your skin that houses important structures and nerve endings, allowing you to feel sensations and providing your skin with strength and elasticity.

Hypodermis (subcutaneous layer)

This layer is like the foundation of your house, providing support and insulation. 

It contains fat cells and connective tissue which provide cushion for your organs and help regulate your body temperate. It also contains all your blood vessels that supply oxygen and nutrients to your skin cells.

So, imagine that your skin as a house with three essential layers: the tough outer roof (epidermis), the supportive walls (dermis), and the strong foundation (hypodermis). Each layer plays a vital role in keeping your skin healthy and functioning properly.

Now, imagine that the epidermis has a special security system made of oils and proteins. These oils act like a protective shield, keeping moisture in and bad stuff, out. The proteins, like guards, help repair any damage that might happen to the wall. This is your skin’s barrier.

Think of your skin barrier as a protective shield that keeps your body safe. When the skin barrier is impaired, it's like there are cracks or holes in that shield, making it easier for bad things to get through.

These cracks or holes can happen due to various reasons like using harsh ingredients in your skincare, harsh weather or working in constant aircon, or even some medical conditions and medications. When the barrier is impaired, it can lead to problems like dryness, redness, irritation, and even infections because germs can sneak in more easily. With the right care, your skins' barrier can be repaired and strengthened again.

Let’s understand what your barrier is made up of. You have two main layers of your barrier, a water layer and an oil layer

Think of the oil layer as a protective coat of oil that keeps your skin healthy and strong. This oil layer is made up of special fats called lipids and just like how oil protects a car engine from rust, the lipid barrier protects your skin from damage.

The purpose of this lipid layer is to:

  • Lock in moisture – Oil is denser than water and so it sits on top of the water in your skin, locking it in to prevent TEWL (we’ll get to that shortly).
  • Keep all the bad stuff out – The oil acts as a barrier against dirt, germs, and other harmful things that can cause infection and irritation.
  • Maintain skin pH – It helps keep your skin’s natural acidity level balanced, an important step in keeping your skin healthy.

Now imagine the water layer in your skin like a refreshing drink for your skin cells.

The water layer, also known as your hydration layer has very important purposes:

  • Moisture balance – It helps keep your skin hydrated by holding onto water, keeping your skin cells plump and healthy.
  • Skin elasticity – If your skin is well hydrated, it is more elastic and flexible, it can stretch and move more without damaging easily. This means gravity can’t take hold as easily of those fine lines and wrinkles!
  • Nutrient transport – Water in the skin helps to transport essential nutrients to your skin cells, keeping them well nourished and functioning properly.

So if you’re thinking of your skin as a fortress, your barrier is the sturdy wall that protects the castle (your skin and body) from invaders, the lipid barrier is the defence shield, protecting you from harm and your water barrier is strengthening all your cells and making sure everything is functioning as they should.

Both layers are crucial for keeping your skin resilient, strong and healthy.

Now I want to explain TEWL.

T.E.W.L stands for Trans Epidermal Water Loss

TEWL is basically the amount of water that escapes your skin into the air. Naturally this occurs daily through sweat and humidity in the air however it is important to re-nourish your skin to replace the hydration that we lose daily.

If TEWL is high, it means your skin is losing more water than it should, which can lead to dryness and other skin conditions. In some parts of Australia, where the humidity is generally high, there is already a lot of moisture in the air so your skin might feel more hydrated. Areas with lower humidity, can cause dryness and dehydration in the skin due to the evaporation of water. Factors such as weather, harsh skin care products, over exfoliation and some skin conditions can affect TEWL.

Now, back to your skins' barrier. Imagine you have a glass of water, and you have a layer of oil on top of that water. The water (and all the nutrients it is holding) will be locked in and protected by the lipids. Now if your roof had holes or leaks, water could escape and damage the foundation of your house. Similarly, if the lipid barrier is compromised, harmful things can seep into your skin and disrupt the water barrier. Leaving your skin feeling irritated, dry and sensitive.

But how do you know if your skin’s barrier is impaired?

Are you feeling dry and sensitive? Is your skin feeling tight and rough textured? Do you suffer from skin redness?

There is a difference between your skin being a ‘true dry’ skin and just being dehydrated from an impaired barrier. Allow me to explain the difference..

Dehydrated skin:

Think of dehydrated skin like a thirsty plant, it’s lacking water. Signs might include:

  • Feeling itchy or tight, especially after cleansing your face.
  • Looking dull and tired.
  • Noticing fine lines and wrinkles more.
  • Feeling rough or bumpy.
  • Oil imbalance, your skin may feel extra oily as your skin is trying to ‘overcompensate’ and produce more oil to keep itself hydrated.

Dry Skin:

Dry skin is more like a desert without enough moisture, this is when your skin is lacking oil. Very few people have a ‘true dry’ skin type and it is usually genetic. Signs may include:

  • Feeling rough and tight all the time
  • Flakiness or peeling
  • Redness or irritation
  • Severe cases can have cracks or fissures in the skin


If you’re unsure if your skin is dry or dehydrated, try this simple test: Wash your face and wait a few minutes. If it feels tight and uncomfortable, it might be dehydrated. If it feels rough and lacking elasticity, it might be dry.

Both conditions can be treated with gentle skin care, however both are treated slightly different. It all stems down to your skins' barrier. If that lipid oil layer of the barrier is too thin, harsh products will penetrate too deeply, too fast causing that irritation and sucking all that water hydration dry. 

It is always important to check the ingredients you are using and if they contain harsh chemicals or alcohol that may be stripping your barrier down.

We use O Cosmedics in salon and are confident that all the active ingredients they use in their products are going to benefit your skin and strengthen your barrier. Free consultations are offered with any of our skin therapists to discuss what options might work best for your individual skin concerns. 

Kiara has been in the industry for almost 10 years. She is passionate about all things skin and beauty and has learnt a lot from all the clients and therapists she has met during this time. On her days off she loves laying on the beach and reading her book in the sun (with her O Cosmedics SPF of course).

Salon Manager
Complete Skin & Beauty Mango Hill

Leave a Comment or Question

What did you think of this article?
First and Last Names
E-mail Address