A waterproof wrapping for the whole body and the first line of defence against bacteria. Skin also cools you through sweat and senses pain, temperature and pressure.

Acne is caused by a build-up of dead skin cells and oil. It is not caused by a lack of hygiene.
Sunburn is a radiation burn from the sun's UV rays.
Dermatitis means inflammation of the skin, and it has many different triggers.

How it works

The skin has three main layers. The epidermis is on the surface, the dermis below it contains collagen fibres for strength, and the subcutis is a layer of fat. As old, dead skin cells are shed from the surface, new ones are pushed up to replace them.

Your body makes vitamin D when bare skin is exposed to the sun. The sun's ultraviolet (UV) radiation is also the major cause of skin cancer, so sun protection is recommended when the UV Index is 3 or above.

Connections

9 connections on the map. Select a topic to read its page.

Skin is affected by

Sun exposure and UV
The sun's ultraviolet (UV) radiation is the major cause of skin cancer.
Sources: Cancer Council Australia, Vitamin D; Better Health Channel (Victorian Government), Skin explained
Eczema
Eczema causes areas of red, dry, itchy skin.
Source: healthdirect Australia, Eczema
Skin cancer
The 3 main types of skin cancer are named after the type of skin cell they start from.
Source: Better Health Channel (Victorian Government), Skin cancer
Psoriasis
Psoriasis may cause red, itchy, scaly patches on the skin.
Source: healthdirect Australia, Psoriasis

Skin is linked with

Acne
Acne is caused by a build-up of dead skin cells and oil.
Source: healthdirect Australia, Acne
Hair loss or thinning
Hair follicles sit in the skin, and inflammation of them is one cause of hair problems.
Source: healthdirect Australia, Hair problems

Skin needs

Vitamin C
Your body needs vitamin C to make collagen, a protein needed for wounds to heal.
Source: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers
Zinc
Zinc helps wounds heal.
Source: NIH Office of Dietary Supplements, Zinc fact sheet for consumers

Skin makes

Vitamin D
Your body makes vitamin D when bare skin is exposed to the sun.
Sources: NIH Office of Dietary Supplements, Vitamin D fact sheet for consumers; Cancer Council Australia, Vitamin D

Sources

Skin explainedBetter Health Channel (Victorian Government), last reviewed 16 October 2023
Vitamin DCancer Council Australia, last reviewed 2 October 2026
Acnehealthdirect Australia, last reviewed October 2025
Vitamin D fact sheet for consumersNIH Office of Dietary Supplements, last reviewed November 8, 2022

Each connection above names its own source. See every source AskBioMap uses.

Summarised from the Better Health Channel, Cancer Council, healthdirect and the NIH Office of Dietary Supplements. Sources read on 13 and 16 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.

In brief