Children who have their tonsils taken out are almost three times more likely to develop asthma and other serious lung diseases.
Scientists say the long-term risks may outweigh benefits in some children, according to Daily Mail.
The tonsils help the body to fight infections but can become badly infected with tonsillitis, which causes them to become painful and swollen.
This study by the universities of Copenhagen and Melbourne studied 1.2 million people across three decades and is the largest study of its kind.
As well as breathing diseases, having both the tonsils and adenoids – similar tissue at the back of the nose – taken out as well increases the likelihood of inflammation in the middle ear and sinusitis.
Researchers suggest doctors should give more consideration to therapies other than removing the tonsils, which could badly affect children’s long-term health.
Tonsillectomy almost triples risk for diseases of the upper respiratory tract, according to the research.
It also showed removing the adenoids during childhood more than doubles the risk of lung disease later in life.
The study looked at the long-term effects of three operations: adenoidectomies, which 17,460 people had; tonsillectomy, which 11,830 people had; and adenotonsillectomies – in which both are removed – which 31,377 people had.
The study published in the journal Otolaryngology Head and Neck Surgery was based on data from 1,189,061 Danish children born between 1979 and 1999.
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