The picture that has women considering giving up their gel manicures for good.

When someone you love gets sick, you want to do everything you can to help them, and if you can, protect others from going through the same.

So when Lauren Heimer’s best friend was diagnosed with melanoma on her thumb, she took to Instagram to educate others about what to look for.

It’s not a huge lump, scar or scab – it’s something you might not even glance twice at.

Image: Instagram/@laurzenheimer

"That's what melanoma looks like on a thumbnail. One of my very best friends in the world got gel manicures regularly, like many of us," she wrote.

"Prior to her diagnosis I hadn't put too much thought into the dangers of the UV light so closely to the fingers/nails especially with some fairly newer chemical compound on them. She no longer has this thumbnail because THANK GOD she was smart enough to go to a dermatologist and he diagnosed her with a rare form of cancer and did some surgery.

"Although she very much misses her 10th nail, she is lucky it did not spread. And I'm so extremely blessed that she caught this in time."

Watch: We test out spray on nail polish. Post continues after video.

Heimer then issued a warning for others who might be in a similar position.

"Please be cautious when getting gels and consider that there are these types of risks. This is just a friendly PSA in honour of my homegirl's thumb, my love for her, and my general concern for humanity."

She said she was sharing the message after noticing many people in her life having gel manicures.

Matte X holo #holonails #holo #matte #mAttenails #nailart #nailpolish #gel #gelnails #lightelegance #lightelegancegel

A photo posted by @nailedbyv on Aug 11, 2016 at 6:56pm PDT

"I'm sure a lot of people could have them and nothing bad would happen but it's just a good thing for people to know about and also see what it could look like so if God forbid they experience this they'll know what it looks like."

This picture has since circulated around many beauty forums online, causing many to declare they would be stopping their gel manicures.

While it's certainly scary, it's important not to scaremonger or freak out.

Internationally-recognised scientist and Co-Chair of the Nail manufacturers Council with over 30 years experience in the cosmetic, beauty and personal care industry, Doug Schoon, responded to the picture after it was sent to him by a concerned nail technician. (Post continues after gallery.)

According to Schoon, noticing a similar stripe on your thumb doesn't necessarily spell 'cancer' immediately, but it's worth paying attention to.

"This is nothing new and is something that all nail technicians should know about. The nail bed often develops dark stripes like this, they are fairly common in those of African descent and not unusual for those of Asian descent. These stripes occur when nail matrix cells begin to produce melanin, which is more common in those with darker skin," he wrote.

"This can signal a potential problem when it occurs in Caucasians. Because they have much less melanin normally in their skin, there should be much less in the nail plate. These stripes rarely turn out to be caused by a nail cancer, but nail cancers do occur. All nail professionals should know this as well. It’s your job to know!"

Technicians should look out for their clients' nail health. Image: iStock

He said there was no evidence that has shown that these stripes are more prevalent for those who regularly get manicures, and that it can happen to men, women and even children who don't go to salons. It can also occur on toenails.

So what should you do?

According to The Skin Cancer Foundation, while the lamps used in nail salons to both speed-dry regular manicures and set gel manicures do emit UV radiation, there's no need to give up your nail habit altogether.

"They predominately produce UVA rays, which have been linked to both premature skin ageing and skin cancer, however even the most intense of these devices presents only a moderate UV risk - a far lower risk than that presented by UV tanning devices," they said in a statement available on their website.

To be safe, they recommend applying a broad spectrum (UVA/UVB) sunscreen to hands 20 minutes prior to UV light exposure when getting gel manicures.

If getting a regular manicure, they advise allowing nails to air-dry naturally rather than using the lamps.

Image: iStock.