Understanding Skin – Going below the surface

sHealthy skin is something that most people would desire, not just for the sake of looks but also because of how important skin is to our body. However, with a diverse variety of skincare products and tips available, it might prove difficult to find out what works for our skin.

To try and figure out the best way to treat our skin, first, we must understand it. Dive on in to learn more about skin functions and structure, and ultimately, about your body.

Functions of the skin

More than often, people tend to forget that skin plays an important role in keeping the body healthy, rather than just being part of people’s natural beauty.

Sense of touch

Skin – the largest organ in your body, covers your entire body and gives you your fifth sense: the sense of touch. There are nerve endings located in your skin that allow you to feel and respond to the external stimulus such as temperature, pain, and pressure.

Protection from sunlight

“Sunlight” here actually refers to UV rays, which can be harmful if you are overexposed to them. Your skin does provide some form of protection against UV rays, but it is usually insufficient, especially for long hours of exposure.

girl wearing hat to protect against sunlight

Temperature regulation

One of the most important conditions for your body to function normally is temperature. Blood vessels located in your skin reach over your entire body, distributing body heat evenly so that optimal temperature is achieved. Not only so, but skin also helps to cool your body down by releasing body heat through sweat.


Skin acts as a barrier against the external environment by preventing dirt and bacteria from invading the body, hence reducing the chances of illness and infections. Sebum, an oily substance, is produced from the skin and creates an acidic platform on your skin so that bacteria cannot further multiply.

Skin also contains a protein called Keratin that stops the bacteria from entering the body. However, bacteria can still enter the body through wounds on the skin. To combat this threat, Langerhans cells that reside in the skin would draw the white blood cells to open wounds to deal with any pesky germs looking to invade.

Excretion of waste

Gross as it sounds, your skin does excrete waste in the form of sweat. This helps to keep your body healthy as it gets rid of unwanted toxins and all the bad stuff. Bye bye toxins!

Protects the inner body

The high elasticity of skin helps to reduce the chance of injuries by holding up to physical pressure. It also cushions and absorbs shock from any impact. This way, it helps to protect your inner organs from any injuries that might occur.

Vitamin D

Essential for calcium absorption and bone growth, this vitamin is produced when the skin is exposed to sunlight. The skin also helps to store this vitamin to aid in the growth of healthy bones.

Structure and layers of the skin

There are three main layers of the skin, namely the epidermis, the dermis and the hypodermis.


This is the outermost layer of skin that is visible to your eyes. It acts as a protective barrier to external aggravation such as pressure and heat and also limits the loss of important nutrients and water from your body.

However, the epidermis only has a thickness of 0.1 – 0.3mm, making it the thinnest layer among the three. Melanin, the pigment that for skin colour, is also present in the epidermis.

This layer is constantly renewing itself where it gets rid of the dead skin cells and produces new ones. This keeps the skin able to continue its important role in ensuring the body’s health.


This is the layer of skin that lies between the epidermis and the hypodermis. It mainly contains collagen and elastin along with connective tissues. The dermis is an elastic and firm layer and is usually ten times thicker than the epidermis. Other components of skin such as hair follicles, nerve endings, and sweat glands reside in the dermis.


The hypodermis lies right below the dermis and consists mainly of subcutaneous fat. This creates a thick and firm layer that helps to cushion any physical pressure and also acts as an insulator to keep body heat in so as to maintain optimal body temperature. Connective tissues are also present to help to heal any damage done to the skin.

illustration of our human skin is made up of many layers

Characteristics of healthy skin

In general, healthy skin should be smooth and free of blemishes, and none of its usual functions should be impaired.

Skin renewal

As mentioned above, the epidermis is constantly renewing itself. Healthy skin should have a normal rate of skin renewal, where dead cells and dirt are pushed out regularly. This process of skin renewal takes place in a 28-day cycle. In fact, this process depends on how hydrated your skin is. Insufficient moisture would disrupt skin renewal and can lead to acne breakout or skin flaking.

Sufficient moisture

As mentioned, sufficient moisture is required to keep skin at a healthy state where it is neither oily nor dry and functions properly. This moisture comes from water in the skin layers and some from perspiration.

If your skin is too dry, this means that it is not getting enough moisture or it is losing too much moisture. Dry skin usually occurs at cold places where humidity is low and skin dries out easier. This still applies even in a tropical climate like Singapore because air-conditioned places will also dry out your skin just as in colder environments.

On the other hand, the skin should not be too oily either. Oily skin is caused by hormone changes or overactive sebaceous glands. This would result in excessive sebum, which is the most common cause of acne and pimples, which will then lead to blemishes on the skin.

pH of 5.0

Healthy skin will generally have a pH of 5.0, resulting in a mildly acidic environment that will prevent bacteria from living and multiplying on the skin. This will help to reduce the chances of infection or illness from bacteria entering the body through the skin.

It is crucial to maintain this environment as any drastic changes to the pH of the skin might result in a damaged shield against germs. Try to choose cleansers and toners at the same acidic pH that your skin has so as to maintain the environment to prevent bacteria from multiplying.

Protective barrier

Skin in a healthy condition will act as a natural protection for your body. It would play a role as a protective barrier that shields your body from external aggravation and any shock or damage that might come your way. However, this function might be compromised when the skin becomes too dry. With lesser sebum leading to insufficient moisture, the protective barrier is unable to hold up against the external threats.

Different skin types

In order to understand what our skin requires to function properly, we should first take a look at what type of skin we have. Here are the four main skin types listed below – which one do you belong to?

Normal skin

healthy skin cross section

Out of the four skin types, this is the most coveted type but it can be hard to maintain skin at this condition over a long period of time. This skin type is well-balanced and healthy, meaning it has sufficient moisture and secretes sebum at a normal rate.

Normal skin can be identified by its smooth and soft texture and should be free from any blemishes, oily surfaces or chapped skin. This type of skin is usually not considered sensitive and is not prone to redness or irritation.

Dry Skin

dry skin cross section

Dry skin is usually caused when the skin produces lesser sebum, resulting in a lack of moisture to keep the skin healthy. This type of skin can be easily identified by its characteristics such as rough patches and flaking. People with dry skin are also prone to redness and irritation, and in extreme cases, chapped skin.

Oily Skin

oily skin cross section

This skin type is extremely prone to blemishes such as acne and blackheads and is caused by over-production of sebum. The main features of oily skin would be greasy, glossy patches and enlarged pores.

This skin type is normally caused by stress and genetics. Hormone changes are also one of the causes of oily skin, which would explain why acne is a common problem among teenagers going through puberty.

Combination skin

meaning of combination skin

This skin type basically combines oily skin and dry skin into one type. Some parts of the skin will be oily while others will be dry. In terms of facial skin, the T-zone (consisting of the forehead, chin, and nose) tends to be the oily zone while the cheeks (U-zone) would be dry.  Because of its unique characteristics, combination skin can be quite tricky to deal with since the different areas would require different types of skin care.