Do we need our tonsils?

Humans have been taking our tonsils out for a remarkably long time. The first tonsil extractions date back thousands of years, to at least early Hindu medicine practices, and later to the Roman empire. With the advance of surgical methods, tonsillectomies became commonplace in the 20th century. They were once so widely recommended that, in 1921, a Manhattan hospital opened dedicated solely to performing the procedure in poor children. Wealthy donors funded the project under the belief that tonsil removal offered a universal benefit to the less fortunate. 

Though the tonsil hospital closed decades ago, tonsillectomies still remain one of the most prevalent childhood surgeries. By some assessments, rates have fallen since a peak in the 1970s. 

“We’re doing, per 100,000 people, probably 50 percent of what was done in the 1970s,” Ron Mitchell, a pediatric otolaryngologist and professor at the University of Texas Southwestern Medical Center, tells Popular Science. 

But still about 290,000 tonsillectomies are performed in children under 15 years old in the US. each year, according to the 2019 clinical practice guideline for tonsillectomy in children, which Mitchell co-authored. 

So why do doctors so frequently recommend tonsil removal? And why are we born with those fleshy lumps in the back of our throats in the first place, if they so often become problems? 

[ Related: Don’t tape your mouth before bed. ]

What do tonsils do?

Tonsils are organs of the immune system. They’re made up of lymphoid tissue, similar to your lymph nodes, and contain infection-fighting white blood cells. Humans are born with four sets of tonsils that form a structure called Waldeyer’s Ring, where the nasal and oral cavities join up at the back of the throat. The palatine tonsils just behind the roof of the mouth, on either side of the uvula, are the largest of the group, and the ones most often removed in surgery. The pharyngeal tonsils, or adenoids, are at the back of the nasal passage and are also commonly taken out. Additional tonsillar tissue sits at the base of the tongue and at the opening of your eustachian tubes. 

All four of these structures serve a very similar–if not identical–function, Farhoud Faraji, an otolaryngologist and medical researcher at the University of California San Diego (UCSD), tells Popular Science. That built-in redundancy is part of what mitigates the disruption of tonsillectomies, he explains. In the overwhelming majority of cases, some bits are left behind to pick up the slack. 

Normal, healthy tonsils play a role in immune system memory and local antibody production, speeding up your body’s ability to fight off invaders near where they’re most likely to enter the body, says Sydney Ramirez, an infectious disease physician and immunologist at UCSD. Tonsills contain a reservoir of T cells, B cells, macrophages and neutrophils– all white blood cells with their own particular germ-fighting roles. T cells activate immune response and detect interlopers, B cells make antibodies that label problem particles for attack. Macrophages, and neutrophils.engulf and eliminate pathogens and other debris. 

“You have this set of immune cells that can fight off viruses and bacteria that don’t have to travel very far … and can surveil or provide protection as a first line of defense” after ever-important mucus, Ramirez says. In her research, she’s found evidence that tonsils hold on to antiviral memory to combat repeat SARS-CoV-2 infections (the virus that causes COVID-19) and other common bugs over the long-term. 

But, again, “humans have a lot of redundancy,” she adds. If tonsils are removed, the same diversity of immune cells is still present and circulating in the body. “Thankfully, taking out one structure doesn’t mean you’re doomed.”

Why are tonsils sometimes removed?

Over time, as stats on tonsil removal have shifted, so too have the prevailing reasons for it. For decades, tonsillectomies were performed mostly to resolve frequent tonsillitis, an infection of the tonsils caused by Streptococcus A bacteria. Strep throat is unpleasant for anyone, but in the subset of children who get recurrent tonsillitis, it can be especially uncomfortable as bouts of swelling, fever, trouble swallowing, and serious pain come back again and again. Plus strep infections that go untreated carry long-term risks and the potential for complications, like rheumatic fever, notes Ramirez.

Yet improvements in antibiotic treatments and newer research indicating recurrent tonsillitis cases can recede with time mean that strep is no longer the major driver of tonsillectomy, Mitchell tells Popular Science. “Over the last 20 years, there’s been a big decrease in the number of tonsils removed for recurrent infection,” he says. The 2019 guideline he helped write strongly recommends watching and waiting in response to repeated strep infections in most cases, instead of jumping straight to surgery.

Now, the biggest driver for tonsillectomies is to resolve breathing issues. In some children, the tonsils grow faster than the airways. “That’s where you get problems with snoring, mouth breathing, and sleep disordered breathing,” Mitchell says. 

Oversized tonsils can cause obstructive sleep apnea for certain kids–disrupting their ability to get proper rest for months or even years at a time, during a window of crucial brain development, he explains. Again, in many cases, enough time and careful observation might reveal the problem solves itself, as the airways catch up in size. 

However, for children with severe apnea symptoms, that wait might not be worth it. If children are struggling in school, not growing, developing behavioral issues or asthma, then Mitchell and his guideline’s co-authors recommend tonsillectomy–trading a week or two of painful recovery for months of breathing and sleep difficulties. 

Does tonsil removal carry any risks?

As with any surgery involving general anaesthesia, there is a risk of adverse or allergic reaction. Bleeding post-surgery is another potential (though rare) short-term risk that can ultimately lead to additional surgery to patch up, Mitchell says. If pain isn’t managed well enough in the aftermath, children might stop drinking fluids and become dehydrated–another possible complication.

Then there’s the debate over the longer-term consequences of tonsil removal. Because they’re immune organs, a spate of studies have examined whether those who’ve had their tonsils taken out end up with immuno-differences or deficiencies, compared with those who haven’t. The vast majority of research examining clinical markers of immune function, like white blood cell counts and antibody levels, finds no significant difference. 

Despite that, some large cohort studies have found that children who’ve had tonsillectomies or adenoidectomies show a small, but significantly increased incidence of respiratory illness– including infections, allergies, autoimmune diseases, and asthma–throughout their lives, compared to those with their tonsils intact. Other cohort-based research indicates an association between tonsillectomy and slightly higher risk of multiple types of cancers. 

Yet the difficulty with all of these cohort studies is that they cannot determine cause directly, only correlation, notes Ramirez. It’s possible that tonsillectomy is linked to cancer risk because lymphoid tissues play a role in identifying and eliminating cancerous and precancerous cells early on. But it’s also possible that people with recurrent tonsillitis or breathing issues in childhood were already predisposed to certain cancers and respiratory illnesses. Or that having had your tonsils removed in childhood indicates something about your level of medical care access and exposure– perhaps making you more likely to later see a doctor for an infection or get diagnosed with cancer. “We don’t know,” she says. 

What is clear is that removing tonsils is an effective and near immediate treatment for some children’ s breathing difficulties and a handful of kids’ recurrent strep infections. 

[ Related: When surgery was a public spectacle. ]

Tonsillectomies past and present

In decades past, tonsillectomies were perhaps done without enough consideration of the costs vs. benefit. Procedure rates varied more based on location than by any actual clinical indicators of need. In one Vermont town, for instance, around 70 percent of children had their tonsils removed in the 1960s, versus 20 percent in a neighboring municipality. 

Now, the guidelines for removal are standardized and physicians tend towards a more cautious approach. “We never take out tonsils for no indication,” says Faraji. And where it is indicated, it’s for good reason, he adds. 

“There’s always been concern about the overuse of surgery,” says Mitchell, and it’s important to ask those questions and consider the big picture. “It should only be done when the benefits of surgery far outweigh the risks,” he adds. “The majority of children do not need a tonsillectomy.” 

But when done for the right reasons, tonsillectomy offers a meaningful and quality of life boost. “We have very happy families who often will say, one month out, it’s the best thing they ever did.” 

This story is part of Popular Science’s Ask Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something you’ve always wanted to know? Ask us.

 

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