You may have realised that the skin is the largest organ of the body. If the skin of an average adult was stretched out, it would cover a total area of about 1.8 square metres (20 square feet). It carries out several essential functions, such as protecting us from microbes and the elements, regulating body temperature and facilitating the sensations of touch, heat and cold.
Our skin has three layers. They are the:
- Epidermis – the outermost layer of skin, provides a waterproof barrier and creates our skin tone.
- Dermis – beneath the epidermis, contains tough connective tissue, hair follicles and sweat glands.
- Hypodermis – the deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue.
Within the structure of the skin are also found:
- Blood vessels – to help keep body temperature constant (blood vessels in the skin dilate in response to heat or constrict in response to cold).
- Sebaceous glands – secrete sebum, an oily substance that helps keep skin from drying out. Most of the glands are located in the base of hair follicles.
- Sweat glands – when your body gets hot or is under stress, these glands produce sweat, which evaporates to cool you down.
- Hair follicles – every hair on your body grows from a live follicle with roots in the fatty layer called subcutaneous tissue.
- Collagen – a protein which makes up 75% of your skin. If you have plenty of collagen you will not have so many wrinkles. Collagen levels diminish as we get older.
- Elastin – found with collagen in the dermis. It also deteriorates over time and skin sags.
- Keratin – the strongest protein in the skin giving it rigidity.
The skin’s colour is created by special cells called melanocytes – they produce the pigment called melanin.
Know your own skin
Your skin can reveal many things. Dry and dull skin can be a sign that you are dehydrated or that you have a poor diet and are lacking nutrition. Combat this by drinking plenty of water and making sure that you get your 5 a day of fresh fruit and vegetables.
Very pale skin can indicate that you have anaemia and that you should get your iron levels checked out. If your skin is itchy, this could be a sign that you have problems within your vital organs such as the kidneys, liver, thyroid and pancreas.
Dry and itchy skin can also be caused by a reaction to creams and washing powder.
Other skin problems
Extremely dry skin can be an indication of hypothyroidism. But if your skin is sweaty, it can be due to hyperthyroidism. Both of these conditions should be investigated by a doctor.
If your skin is red for no apparent reason, it could be a condition called Rosacea. Another chronic condition, called lupus, can cause reddening of the skin in the shape of butterfly wings.
If your skin looks like it has a sun tan but has not been exposed to the sun it could be caused by excess of iron or because of a disorder called Addison’s disease.
If the skin develops a blueish tint (cyanosis) this can indicate that there is insufficient oxygen in the blood. It could be due to lung or heart problems or circulation disorders. On the other hand, a yellowish colour could mean a liver condition called hepatitis.
Some medications can cause skin changes and it is important to be on the lookout for these. You can normally find a description of potential side effects on the leaflet that comes with prescribed and over the counter medication. If you are at all concerned about a side effect you must always speak to a doctor right away.
It is important to get any changes in your skins colour or texture checked out by a doctor. It is especially important to let a doctor look at any lumps, bumps and moles or freckles that have changed in appearance. This means that they have changed in size or colour or have started to bleed.
Your doctor can refer you to a dermatologist if you need further tests to check out exactly what is causing the problem.