Thirty years ago, tonsillectomy - the surgical removal of the tonsils - was a common childhood operation. But between 1967 and 1980, rates declined significantly. In the 10 years from 1970, the number of operations fell from 95 per 10,000 people to 70 per 10,000. No one is quite sure why tonsillectomy rates dropped so dramatically, says Richard Maw, consultant otolaryngologist at the Bristol Royal Infirmary. "It may be that doctors simply got better at deciding who should have their tonsils removed, or perhaps it was because kids were getting fitter. We just don't know."
Nowadays, surgeons will usually only remove tonsils if a child is suffering frequent attacks of severe tonsillitis involving a lot of time off school and high-temperature episodes which put them off their food. Left to their own devices, most children grow out of their condition; by the early teens, swollen tonsils tend to shrink to their normal size and will eventually stop their tendency to infection.
Throat problems, however, pursued Jo into adulthood, with full-blown attacks of tonsillitis giving way to a more chronic condition. "I went to my GP countless times, often with enlarged glands in my throat, but more usually with a kind of general malaise," she says, "I woke up every morning with a sore throat - I thought everyone did - and spent most of my adult life feeling really down and tired all the time. My doctor tested me a couple of times for anaemia, then just put it down to stress and being a single parent."
She also began to suffer from regular bouts of bad breath. According to Ghussan Alusi, a surgeon at the Royal National Throat Nose and Ear Hospital and lecturer at University College London, tonsils are not always smooth, but can form craters where food can collect.
"Particles of food would get trapped in these pockets and rot, giving me terrible breath as well as creating infections and swelling in my throat," Jo says. "It was really embarrassing; I became very self-conscious about getting too close to people when it was particularly bad."
It was not until she saw a locum last year, rather than her usual GP, that it was suggested Jo see an ear, nose and throat (ENT) specialist. The consultant gave her two options - a six-12 month course of antibiotics or a tonsillectomy. As she did not want to take more antibiotics, she opted for surgery.
Although removing tonsils is a relatively simple operation, it can be more difficult in adults where repeated infections have created extensive scar tissue. Adults usually take longer to recover than children, and also experience more post-operative pain.
"It was absolutely horrendous," admits Jo, who took three weeks to recover. "Although I was discharged the day after the operation, I had the most dreadful sore throat I had ever had in my life. They told me to eat crisps and 'raspy' foods to stop scar tissue building up, but it hurt so much that I could hardly swallow my own saliva. I couldn't even cry because it made my throat tighten and that was just too painful.
"The hospital gave me some painkillers, but they didn't help at all. In the end, I got so desperate that I phoned my GP, who prescribed me much stronger pills, which at least allowed me to get a few hours' sleep. If I'd known what it was going to be like, I probably wouldn't have done it."
But six months down the line, Jo, like many others, feels very differently. Removal of the tonsils has been proven effective in reducing symptoms - a US study in 1984 showed a reduced incidence of throat infections for two years following the operation, while a Scottish tonsillectomy audit published last year found that 98 per cent of people were glad they had the operation.
So has the trend not to operate on children gone too far? Martin Bailey, consultant ENT surgeon at Great Ormond Street Hospital for Children, London, says that although most children grow out of tonsillitis attacks, in some "it does just go on and on, and if left will continue into adulthood. The pendulum has swung the other way to some extent - GPs and paediatricians have perhaps over reacted a bit." The more conservative approach, he says, means "there are some much older children and adults who have been told to wait and we see them come in as teenagers and young adults with problems.Having your tonsils out as an adult is not much fun".
Still, he believes, "it's better to operate on too few that too many. If there are a few individuals who continue to have trouble, you can still do the operation later. And they are the exception rather than the rule".
Jo Finch says the operation has changed her life. In the year leading up to the operation, she had to take 10 weeks off work and was worried she would lose her job, but since having her tonsils out, she hasn't missed a day. "I've got so much more energy; I just don't get tired like I used to. I don't wake up every morning with a sore throat, I don't get smelly breath, I don't get bouts of depression completely out of the blue and I can go out on my mountain bike without it leaving me exhausted for days.
"I have just applied for a full-time job actually believing that I can do it - before the operation, I just couldn't see how anyone could manage it. It's wonderful. I feel so much more in control of my life".
Why the germ police cop out
Tonsils and adenoids, situated at the upper air and food passages, are formed from lymphoid tissue that deals with overall policing of infection. Newborn babies inherit immunity to infection from their mothers, but as that passes away after a few months, the tonsils and adenoids begin to sample the foreign particles that pass through the mouth and nose, and present them to the lymphatic system which produces antibodies.
The tonsils do not actually kill bacteria, so by five or six, when children have already sampled most bacteria in their environment, the tonsils become less useful. From about seven they start to shrink substantially.
Tonsillitis occurs when the tonsils become infected by the organisms they are trying to detect. In children, an upper respiratory tract infection causes the tonsils and adenoids to swell. As it takes time for this swelling to subside, repeat infections increase their size and vulnerability to attack until eventually they may end up causing more harm than good.
Tonsillectomy is usually carried out around the ages of six or seven, with the adenoids often removed at the same time. Apart from being performed to stop recurrent infection, a tonsillectomy may also be needed if tonsils are blocking airways and causing sleep problems, if there is any any suspicion of malignancy or following an episode of a peritonsillar abscess or quinsy.
The operation takes between 10 and 30 minutes to perform, and involves removing the tonsil tissue from the side of the throat under general anaesthetic. Children will usually need painkillers for between two and seven days afterwards, and typically take two weeks off school. Adults often need a week or so longer to recover.