The unspoken insecurity that strikes fear into the hearts of so many men.

Alexander Skarsgard has sparked a social media frenzy by walking the red carpet with a lot less hair than usual. His new look could best be described as “male pattern baldness” – nothing at the top, a bit at the sides. USA Today has speculated that he’s partially shaved his head for a role he’s currently shooting in The Hummingbird Project.

Still, it’s been enough to draw gasps from his fans.

“WTFFF Alexander Skarsgard better win a damn Oscar for whatever this movie is,” tweeted Joy.

For many people, it comes as a shock to see what is essentially typical male hair loss on a Hollywood actor. Its presence in the media is far and few between.

And yet, research shows that 30 per cent of white men will experience hair loss by the age of 30, rising to 80 per cent by the age of 70. But what many women aren't aware of is just how deeply unsettled men can feel when they start to go bald.

US hair loss expert Dr David Kingsley tells HuffPo going bald can have a devastating impact on men. “A lot of men are suicidal,” he says.

Worldwide, people spend around $3 billion annually trying to halt or reverse hair loss. A CHOICE study found clinics were charging anywhere from $3000 for up to a year of treatment.

Prescription medication costs upwards of $200 annually. Wigs can run into the thousands.

On online forums like HairLossTalk, men open up about their feelings about going bald. They talk about how much they hate anyone running their fingers through their hair, or having to try on clothes in fitting rooms with lots of mirrors and bright lights.

A huge fear is being less attractive to women.

“I remember a girl telling me that she didn't mind my hair loss but if I lost too much more then she could never sleep with me because she could never 'do' a bald guy,” one man posted.

“If I don't respond to treatment, I’ll give up on romantic relationships out of respect to myself and the girls,” another added. “No one deserves a balding, ugly, old-looking guy.”

“I have gone from a life of getting checked out by young girls all the time to a life where, even if I simply look in their direction, I am an old creep,” wrote a third. “I can see it in their eyes.”

A study done in the UK last year – by a hair transplant clinic – seems to have at least partly justified their fears. The study showed that a patient from the clinic got 75 per cent more matches on Tinder following his hair transplant.

Melbourne psychologist Catherine Madigan tells Mamamia men can feel the same insecurity about hair loss that women can feel about any given body part.

“It’s a bit like women saying, ‘Does my bum look big in these jeans?’” she says. “We can all be self-conscious about a flaw in our appearance but I suppose it’s how preoccupied we are with it.”

Madigan has had men come in to see her, genuinely distressed about losing their hair.

“Some of these people won’t leave their house, they won’t socialise, they won’t walk down the street, they’re spending hours researching hair transplants or toupees or whatever,” she says.

Listen: Meanwhile, women just want to get rid of a particular type of hair. (Post continues after audio.)

Madigan says if you know someone who is feeling insecure about going bald, it helps to reassure them that "they're still sexy and you still love them".

But she says in some cases, men’s preoccupation about going bald can be a form of body dysmorphic disorder. If so, reassurance from loved ones isn’t enough. Encourage them to seek specialist help.

“If it’s taking over someone’s life, then they really need to see their doctor and perhaps discuss whether they need to get some anti-depressant medication – because that can help people with body dysmorphia – and organise a referral to a psychologist who specialises in that.”

Meanwhile, Sydney psychologist Gemma Cribb says we’ve become a very body image-focused society, and that has an impact on men as well as women.

“Now we’ve got Instagram and dad bods and celebrity goss magazines and Netflix – everything that we can consume in terms of media – and it certainly conditions people to think there’s a right way to look and a wrong way to look.”

Cribb says baldness is often related to testosterone and virility.

“The more testosterone you have, the more hair loss you’re likely to have, and the more virile you should be.”

If a man you care about is struggling with hair loss, Cribb says you need to treat it like you would any body image issue.

"You’re looking at the same sort of advice you’d give anyone with body image issues, starting to define yourself as more than just what you look like, and looking at the people that are nearest and dearest to you, and asking, are they only around because I have hair? People get very focused on one issue but most of the people they care about don’t care about those issues," she says.

The overriding message is that it's important for each of us to be mindful of just how emotionally affecting the process of hair loss can be for the men our lives. And when it happens, we need to be there to support them through it, and to ensure they know they are loved no matter what.