Experts have warned festive trees can cause 'Christmas tree syndrome' – an allergic reaction that can potentially cause serious asthma attacks.
The danger can come from both real and artificial trees.
Real trees like cypress and pine can collect high amounts of pollen from other plants before they are cut down, which can trigger asthma and hay fever symptoms.
Artificial trees can gather dust, dust mites or even mould in storage.
Reactions from Christmas tree syndrome range from severe asthma attack to wheezing, sneezing, coughs and sore eyes.
National Asthma Council's Sensitive Choice Program Manager David Furniss, said most people were unaware real Christmas trees could harbour pollen and trigger asthma and hay fever symptoms.
"Pollen can have a big impact causing your asthma symptoms to get worse," he said.
"Artificial trees can be a safe alternative but, if used year after year, they accumulate dust, dust mites and even mould in storage.
"Even the most exciting part of the Christmas tree tradition – decorating – can put you at risk too, if decorations in storage have become dusty."
The National Asthma Council Australia has advised people to hose down their real trees before bringing them into the house, to help wash off allergens.
Artificial trees, wreaths and ornaments should be wiped with a damp cloth to remove dust.
When it comes to packing away Christmas decorations, everything should be tightly sealed so items collect less dust, it advised.