For diabetics who don't look after themselves, the long-term risks are damage to the eyes, kidneys, nerves, heart and major arteries. One of the biggest dangers is losing a foot or leg to gangrene: diabetics are 15 times more likely to have an amputation because of the way the disease affects the circulation of blood to the extremities.
"For that reason I've always strived to keep my blood glucose, blood pressure and cholesterol levels as near to normal as possible," says Anna. But despite her best efforts, at just 36, she had to have part of her foot amputated due to the complications of her illness.
Last year, her right little toe and part of her foot were removed in emergency surgery after she developed life-threatening gangrene.
For months after the surgery she was unable to stand on her injured foot and she had to have further corrective surgery on the amputation in April.
It has taken hours of physiotherapy to teach her how to balance and walk again. As a result of the strong antibiotics she's been taking, she's also lost three stone in weight, going from a size 12 to a size six. Only now, one year on, is she strong enough to return to work.
The fact that diabetics have poor circulation makes them particularly vulnerable to severe infection and gangrene, as the blood flow that carries infection-fighting white blood cells to the extremities is so poor.
Diabetes can also cause a loss of sensation in the feet, called neuropathy, which can mean that a foot injury is not felt or noticed.
Consequently, a relatively small foot infection can easily develop into dead tissue and blood poisoning.
Yet despite the number of people affected by the disease, care for diabetics is a Cinderella service, according to the charity Diabetes UK.
Its recent research shows that more than a quarter of diabetics at high risk of having an amputation are not offered any kind of specialist appointment. The study also found that two in five diabetics do not receive advice on how to prevent and treat foot infections.
"It is shocking that some people with diabetes are getting sub-standard specialist foot care, or even none at all, if they are at high risk of amputation," said Douglas Smallwood, chief executive at Diabetes UK.
There are almost two million people with diagnosed diabetes in the UK and it is believed there are 750,000 more who do not realise they have the condition, who could also be at risk of gangrene and amputation.
Latest figures from the Information Centre for Health and Social Care show that diabetes diagnosis has risen from 3.6 per cent to 3.7 per cent of the UK population in the past year.
Mr Smallwood describes the figures, released three months ago, as nothing short of an epidemic. "These statistics mean there were 70,000 people newly diagnosed with diabetes in the past year alone."
Anna's diabetes is type 1, which means her body is unable to produce any insulin at all and she has been reliant on injected insulin since she was a child.
But this is the less common type, accounting for just 5 to 15 per cent of cases. On the increase in the UK is the far more common type 2 diabetes, which develops when the body doesn't produce enough insulin, leading to high blood sugar levels. Type 2 is strongly linked with being overweight.
And with four million Britons deemed to be clinically obese, it's little wonder that diabetes figures are rocketing.
"We've got to make sure diabetic people get the right treatment. All too often it's an underfunded and second rate service," says podiatric surgeon Mike O' Neill, spokesman for the Society of Chiropodists and Podiatrists.
Anna's story is sadly all too typical of such cases. It starts in August 2006 with her purchase of a new pair of shoes for work.
"I knew I had to wear sensible shoes because of my diabetes, so I bought myself a simple pair of flat black moccasins. But it's a purchase I'll regret for the rest of my life."
Within days, the shoes were rubbing and Anna developed a blister on the outside edge of both her feet near her little toes. She went straight to her GP, who referred her to a chiropodist.
"Initially, the blisters were treated with a seaweed dressing, which I was told would promote healing," she explains.
"But within two weeks the infection had worsened and I went back to my GP for antibiotics.
"Three days later I was still so worried I went straight to my local A& E department at King George Hospital, Essex. Initially, I was told I needed to have both the wounds on my feet debrided, which means cut open, cleaned out and stitched up, followed by a month off work. I was shocked but not surprised as I was in a lot of pain."
But in an unfortunate series of events, Anna found herself caught up in an episode of what she claims is a marked lack of proper care.
She explains: "I sat in the consulting room while my doctor was passed from one ward to the other and back again, with everyone insisting I was not their problem. By the end he was shouting down the phone in an attempt to get me treated.
"Finally, after a wait of several hours, the surgical team admitted me for assessment. But once I was on the ward, another doctor took one look at my feet and completely contradicted what the A& E doctor had advised.
"He said it was just blisters and told me I did not need the debriding procedure after all. Instead, he said he would keep me in overnight for observation and send me home in the morning with stronger antibiotics."
And so Anna went home as instructed. She returned to her GP for outpatient dressings and treatment to her feet on the following Monday. But she is convinced that her alleged mismanaged stay at the hospital contributed to the disaster that ensued.
"My feet were treated and dressed by the GP practice nurse daily for a fortnight. But soon, it all went horribly wrong. I had the foot dressed on a Thursday morning and was told to come back on Monday.
"On the Saturday, however, I noticed the skin was looking grey. I should have gone to hospital there and then but I soon began to feel absolutely dreadful and too ill to move. I was living on my own and rapidly became delirious. I spent the night alone at home with a raging temperature, unable to think straight.
"Finally, I managed to pull myself together and get to the phone to call my mother."
Once Anna raised the alarm early on the Sunday morning, her family rushed to help and found her to be nearly unconscious.
"What's more, the smell of decay from my foot literally hit them in the face as soon as they opened the door," says Anna.
Anna was admitted to hospital, but by then the side of her right foot was black - gangrene had set in. The flesh was literally rotting and she was at risk of dying from blood poisoning.
"The only solution was an immediate amputation. I knew I had no option but to agree," says Anna.
And so she had her little toe and the side of her foot - the metatarsal area - surgically removed on September 25, 2006.
Today, Anna is angry about what happened and wants to speak out, not only to warn other diabetics but to raise awareness among health professionals about the dangers of foot problems and diabetes.
Although she believes she may have a legal case against King George Hospital, she is not pursuing it. She says she wants to move forward with her life and does not believe in the compensation culture.
"I've lost enough time already," she says, remarkably cheerfully.
"I don't want to spend years chasing a case through the courts. What I need now is to get well and look to the future.
"But I do want to speak out in order to alert others to what happened. This has cost me a year of my life and left me permanently disabled at the age of just 36, all because I didn't get the simple treatment I needed."
For more information on diabetes visit www.diabetes.org.uk