Holidaying for a long period during new year and Christmas can interrupt your body clock and leave you with symptoms similar to having travelled to a different time zone, scientists say.
People taking extra-long festive break face risk of being hit by a phenomenon called social jet lag when they return.
According to the Daily Mail, the condition can leave people struggling to get up in the morning, feeling sluggish, finding it difficult to fall asleep at night and feeling sleepy during the day.
Other symptoms include indigestion, loss of appetite, difficulty concentrating, memory problems, clumsiness, feeling generally unwell, lack of energy, fatigue and irritability.
On top of that, negative emotions associated with the holiday season being over and two weeks of irregular sleeping patterns could lead workers to feel tired and lacklustre, experts say.
{{/usCountry}}On top of that, negative emotions associated with the holiday season being over and two weeks of irregular sleeping patterns could lead workers to feel tired and lacklustre, experts say.
{{/usCountry}}Social jet lag is described as the difference between biological time and external requirements.
It also causes a problem for teenagers, who will find it difficult to wake up for school.
"Over the Christmas period we will enjoy staying up late at night and staying in bed in the morning," Victoria Revell, a researcher from the University of Surrey, was quoted as saying.
"However, this will allow our body clock to drift later in time similar to flying a couple of time zones west," she said.
"This means that when we go back to work in the new year our body clock will be set later than we want it to be so we will really struggle to wake up, get up and get going in the mornings.
"One way to enjoy the festive season but not let our body clock drift too far is to ensure that we still get up at a reasonable time even when not going to work."