Twinkly candles, cheery teapots, woolly socks and cushions: these are the domestic trappings needed this winter to create a cosy sense of Danish “hygge”. But if the prospect makes you nauseous, do not despair. There is a potent antidote available for an overdose of Scandinavian kitsch that is just as old as the original concept of “hygge”.

The word “uhygge” describes the exact opposite of cosy: it is the name for the unsettling feeling that you are being watched from the forest. Perhaps by a troll or an evil witch.

So, as Britain’s enthusiastic commercial assault on Denmark’s popular notion of hygge continues, a growing number of Danes are keen to remind foreigners of the dark flip side of their national psyche. It seems the trolls that stalk their imaginations are on the move and are planning to fight back.

“There is an idea now about us Danes all sitting around the fireplace eating cinnamon buns, but people also need to know about our strong dark sense,” said Malene Hartmann Rasmussen, the acclaimed artist and ceramicist who makes a study of the shadowy corners of Danish folklore.

“As a nation we have had to find a balance, otherwise we would get a bit sick of all the cosiness. It is a country that has the happiest people in the world statistically, but which also has a very high number of depressed people. We are both, which is really crazy.” Rasmussen, 43, who now lives and works in east London, suspects the powerful opposing concepts of hygge and uhygge are due to the sharp contrast between light and dark in a country that – at its extremes – can go from perpetual daylight in the summer to near 24-hour night at the winter solstice, now a month away. This duality runs through everything.

Also at the centre of this reaction against hygge is the academic Lars Christian Kofoed Rømer, who was once roundly “trolled” himself in the media when it was revealed that he had been granted 2.5m kroner (£300,000) to research the Danes’ relationship with their mythical trolls. His investigations have since closed in on Krølle Bølle, the star of a popular myth about the island of Bornholm in the Baltic Sea. Stories about this king of trolls can be dated back to the work of the writer Ludvig Mahler in 1946, but Rømer is now investigating a much earlier legend about a creature who lived underground and emerged each night.

“It should not just be a discussion about whether he exists or not, but a story about how we become attached to a place,” the academic said. “It can be about creatures – most people are familiar with Krølle Bølle, but there can also be special places in nature that have unique vibes.”

Rasmussen’s newest artworks also focus on trolls, as well as on a black monster, part based on her dog and partly on a bat. “I have been reading a lot of the old fairy tales once told to Danish children and now held in our folk archives,” she said. “The trolls were the way we tried to explain the things that threatened us and that we could not really understand.” Her recent work salutes the other traditionally spooky emblems of the “uhyggelig”: spiders and ugly forest worms. Creepy ceramic creatures peer out around her specially designed rooms, each inspired by childhood memories of the forests to the north of Cophenhagen.

“I always felt drawn to darker things. It is in my blood,” Rasmussen said. “When I was little my grandmother gave me a book called I Troldeskoven (In the Troll Woods) with amazing drawings and paintings by the Swedish painter John Bauer. It is a book that really stayed with me.” The artist has a show in Limoges, France, coming up, but is also preparing her large installation, also called I Troldeskoven, for Collect, the Craft Council’s annual contemporary object fair held in the Saatchi Gallery in February.

Images of smiling Danes in bobble hats may have taken precedence, but the chilling side of Scandinavian culture lurks just out of view. The British appetite for dark films from Danish directors such as Nicholas Winding Refn and Thomas Vinterberg has not gone away. Nor has the influential flow of books and television thrillers billed as Nordic Noir been stemmed. Netflix has now ordered its first original series from Denmark, The Rain. Co-created by Jannik Tai Mosholt, a writer on hit shows Borgen and Follow the Money, it is set a decade after a virus has wiped out most of Scandinavia and is made by Miso Film, the Danish-based production company behind Modus, BBC4’s next foreign language thriller. The award-winning Modus, now being heavily trailed on air by the BBC, is adapted from Fear Not, the fourth book in a series by Anne Holt. It follows the investigation of a spate of disturbing deaths during Norway’s icy festive season.

Meanwhile, in Reykjavik this weekend, thriller writers have assembled to mark Iceland Noir 2016 and will be raising a metaphorical glass to the haunting themes that keep their international readers wanting more. One of the headline authors is the Danish crime fiction star Sara Blaedel, who writes about Copenhagen detective Louise Rick in books now published in 31 countries. Her latest, The Lost Woman, comes out in English in February. Blaedel believes the national talent for creating unnerving entertainment is now a modern tradition and points to the uhygge work of Katrine Engberg, whose first book, Krokodille Vogteren (Egyptian Plover), was published this spring.

Britain may well prove just as quick to pick up on the spookier side of kitsch Danish folk culture as it has been to join the queues for scented candles and tea sets. Bristol Old Vic is staging The Snow Queen, perhaps the most sinister of Hans Christian Andersen’s fairy tales, while the latest virtual reality experiment from the BBC also pays homage to Scandinavian folk imagery. The Turning Forest launches next week on Daydream, Google’s VR headset, and will be free to watch. The 3D adventure begins in a magical forest, as a young child stares into the eyes of a fantastical creature.

Many of the key elements of uhygge were already familiar in British culture before the birth of Nordic Noir, as Rasmussen points out. The fairy tales of Andersen and of the German Brothers Grimm have established the mythology of the eerie forest as a shared north European nightmare. In 2000, the notoriously scary television advertisement for Metz, a schnapps-based alcopop, drew heavily on this aesthetic. It featured a supposedly mythical “Judderman” who crept about the forest. Those who grew up in the 1970s will also remember the craze for troll figurines with crazy multicoloured hair. Dreamworks is currently attempting to breathe new commercial life into these creatures with the animated children’s film Trolls. In this it is the Bergen, the unhappy, lumbering beasts who devour trolls, who provide the uhygge element.

The Danes defiantly claim that hygge means much more than our word “cosy”. It is also about an inclusive atmosphere, they say. And about sharing and food in the glow of candlelight.

But perhaps the most essential element is a sense that no harm can come to those who bask in hygge’s warmth. So, remember this Christmas, if you do achieve hygge, it is only possible because of the trolls who malevolently observe from the shadows.

TROLL TALES

Sunshine turns them to stone.

Are they evil? Not always. Some legends feature benign, if ugly, trolls.

The trolls of Zealand are generally smaller than those of Jutland. Trolls should not be confused with nisse, which are closer to dwarves.

Krølle Bølle, perhaps the Danes’ most famous troll, lives on Bornholm island in the Baltic Sea. His name means Curly Bully (because of his hair).

Rock hurling is a popular troll pastime. They create craters or “trolde hul” as they try to demolish churches. A large troll hole can be seen on a hillside near Grønfeld, Jutland.The troll fans’ bible is Danske Folkesagn (Danish Folktales) by Just Mathias Thiele (pub. 1819-23).