Perhaps second only to clogged pores, pigmentation is one of the most frequently discussed topics in Mamamia'sYou Beauty Facebook group.

How to get rid of pigmentation. What to do about pregnancy melasma moustaches. The best serums for treating pigmentation. Are there different types of pigmentation? Why does it look like I've had an espresso thrown in my face?

SO. MANY. QUESTIONS.

It's for this reason we asked some skin experts to give us the rundown on pigmentation, from melasma and post-inflammatory hyperpigmentation, to which pigmentation treatments are good and which ones will make it worse.

So, settle in and keep scrolling for every single question you’ve ever had about your pigmentation, answered.

What is pigmentation?

Dr David Sharp, Specialist Plastic Surgeon at The Sharp Clinics says, "The word 'pigmentation' refers to any pigment, or colour, in the skin; essentially we all have varying levels of pigmentation, based on how dark or light our complexion is. The pigment that gives our skin colour is called melanin."

WATCH: Here are seven ways to improve your skin while you sleep, post continues after video.

What is hyperpigmentation?

Technically, hyperpigmentation is the term for the uneven, mottled appearance on the skin we usually refer to as 'pigmentation'.

"Hyperpigmentation is the overproduction of melanin. This results in dark spots on our face or body."

What is post-inflammatory hyperpigmentation?

"Post-inflammatory hyperpigmentation is commonly caused by a trauma like acne, skin infections or insect bites. Dark spots are often left behind where irritation was present."

In other words, it's the coloured spot that forms in a pimple's place once you've popped it.Fun.

Are freckles and age spots the same as pigmentation?

Short answer, yes.

"All of these are caused by over-production of melanin. Sun or age spots are often caused by UV exposure or trauma to the skin. Most of these spots are harmless, but in some cases, they can develop into skin cancer."

Freckles, on the other hand, are what happens when the skin cells produce too much melanin in response to sun exposure.

Side note - Mia Freedman shares photos of her pigmentation, and tips for living with it, on her Instagram.

What causes skin pigmentation?

Dr Sharp says the two biggest risk factors are: sun exposure and inflammation. And the most enjoyable part? How pigmentation lurks beneath the skin's surface for years until BAM, it's on your face.

"Sun spots and photo ageing are caused by long-term exposure to UV light. This usually presents as an uneven skin tone in our late thirties or early forties."

What is melasma?

Melasma = pregnancy pigmentation that pops up when you're trying to grow a small human in your belly.

"Melasma presents as flat, brown or grey patches on the face - cheeks, upper lip and forehead are the most common areas."

What causes melasma?

Sun exposure, certain medications and thyroid issues can cause melasma, but it's most commonly known as 'the pregnancy mask' because it often forms on the cheeks and forehead during pregnancy thanks to all the hormonal changes.