If you have a real Christmas tree in your house, you better watch out - because you could be affected by 'Christmas Tree Syndrome'.
The syndrome involves hay-fever like symptoms including watery eyes, an itchy nose, chest pains and coughing.
According to experts, it's triggered by the mould that grows on trees when they're kept in a warm room.
"Most of the time mould is obvious in the home, but many people don’t realise that mould also naturally grows on Christmas trees," Asthma UK GP Dr Andy Whittamore told Express.
"This is made worse when people turn their heating on, as the warmer temperature encourages mould to grow faster," he said.
The syndrome reportedly affects one third of people, and is especially bad if you suffer from asthma.
"[Mould can cause] allergic reactions that can trigger asthma symptoms and, in some cases, life-threatening asthma attacks," added Dr Whittamore.