Picture by Shahab Yazdi from Unsplash

This time of year, as the seasons change and summer slides slowly, sullenly and soggily into autumn, your skin gets dehydrated like mad.

If you are dehydrated, your lips will let you know. They are an exceptionally efficient barometer of the rest of you.

The central heating, possibly, the coldness, then heat of the changeable weather, and the forgetting to drink enough water; all these take their toll.

Of your skin, of course, but your lips too, because lips, although they look like skin, are actually part of the digestive system: they're the nearest the internal bits get to the outside. (Except in horror films, obviously.)

Technically, the skin of the lips actually forms a border between the external skin on your face, and the interior (mucous membrane) of the mouth.

Lips are a transition layer between the outer and the inner, so they're a jolly good signal of what is going on with your health and hydration.

Now, the fullness of your lips is mainly controlled by the orbicularis oris muscle, the one which encircles the mouth, and enables you to smile, grimace and grin. Should you wish to do so. Keeping this muscle built up and strong will give fuller and firmer lips, so it's well worth getting stuck in to the old facial exercises. 

Obviously genetics play a part, as always, but you work with what you've got, don't you?

Lips, because they are lacking as many layers as the rest of the face, and contain no oil glands and considerably fewer melanocytes (that's the clever little chaps which produce melanin), tend to be dry. 

Photo by Luka Davitadze /Unsplash

Also, what you see as colour on lips - yours and other peoples is the blood vessels showing through that clear, thin skin. Less attractive, isn't it? (Except to vampires, probably.) 

So your lips really need your help to keep them moist and protected. 

Make sure you use an organic lip balm though, as some of it will inevitably get eaten!