Why Does the Sun Make You Grumpy?

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Helen Foster
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The sun is out – I repeat. The Sun Is Out. This alone is worth of entire blog post as it’s so rare here in the UK at the moment (and it’s best I stop that little bit of ranting now). However, some of you might not be happy about this news. In fact, you might be downright grumpy – and the reason is (drumroll), you’re not wearing sunglasses.

You see, according to a study carried out in Italy recently, people walking into the sun without anything to shade their eyes reported higher levels of grumpiness, anger and aggression.

woman lying on beach in sun

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Why the Sun Can Make You Angry

Why does this occur you ask? Well, theoretically, say the researchers because squinting makes you frown – and frowning lowers your mood.

This happens because when we make facial movements, our brain actually changes the way we feel to fit them. In another study done many years ago, researchers managed to instantly change people’s mood by sticking two golf tees on their head and asking them to try and pull them together. This created the same facial movement of a frown, without people knowing exactly what they were doing – when they were asked how they felt at this point, most of them had felt their mood drop.

The same theory is said to be why some people who get botox find their depression lifting – because they can’t frown any more they actually start to feel happier.

You can also feel happier simply by faking a smile.

The good news about sun-related grumpiness is it’s very easy to fix. Simply nip off to your local glasses emporium and pick up something shady a bit sharpish and see if your mood improves.

If you can’t be bothered to leave the house (because urgh, sunlight), check out this little online selection and see if anything takes your fancy.

If not though, you might have a case of Summer SAD.

If, however, your mood is bad through most of Summer, not just when you go out on a bright day, there might be something else going on.

You’ve heard of Seasonal Affective Disorder – a drop in mood that occurs in winter as days get shorter and darker, but a growing number of people are reporting cases of Reverse – or Summer – SAD where the bright days of summer trigger negative symptoms. These vary between individuals and include a mix of the list below – the key point though is that they arrive as days get lighter or warmer and disappear in winter




Loss of interest in everyday activities

Poor Appetite


Light sensitivity

Discomfort in heat

The condition affects about 5-10% of SAD sufferers who experience symptoms in Summer not winter. It tends to be more common in women.

The cause is unknown, but a common theory is that rising temperatures somehow interfere with the hypothalamus of the brain which controls many mood hormones. Doctors have discovered that Summer SAD sufferers have different body temperatures than the rest of us.

It may also be linked to thyroid function – and anyone who thinks they suffer should get theirs checked.

There’s no current treatment for summer SAD, instead it’s more a case of controlling the effects. Incorporate shade, fans and cool colours in your home and minimise the amount of time you have to spend in direct heat or sun. Keeping hydrated is also important – you’ll feel hotter the less fluid you consume.

If you also want some tips on how to generally boost your mood, you might want to check out our ‘be happier’ guide which includes over 20 proven mood boosts you can try.

Image: freedigitalphotos.net

Who is The Wellness Nerd?

My name is Helen Foster, and I’m a health journalist and wellness author. Publications I’ve written for include Women’s Health, Reader’s Digest, Body and Soul, Good Health at the Daily Mail, and more. I have also written 16 books on health and nutrition.

1 thought on “Why Does the Sun Make You Grumpy?”

  1. He he, it is like that experiment when you ask people their level of happiness, then ask them to hold a pencil between their teeth and ask the same question. Happiness level goes up just by imitating a smile :0)


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