As The Secret Diary Of Adrian Mole celebrates its 30th anniversary, creator Sue Townsend continues to defy blindness and diabetes to bring us more novels, the latest of which is The Woman Who Went To Bed For A Year. Despite all her ailments, the writer tells Hannah Stephenson she cannot believe how lucky she's been in life.

If health issues are anything to go by, Sue Townsend should be feeling pretty sorry for herself.

She has endured blindness and diabetes for years, had a heart attack in her thirties, a kidney transplant in her sixties and is now wheelchair bound, with neuropathy in her limbs.

If anybody should feel like taking to her bed, it should be Townsend, 65. Yet she has left that to the main character in her latest novel The Woman Who Went To Bed For A Year, which sees the eponymous heroine, Eva, a 50-year-old put-upon wife and mother whose kids have flown the nest, do just that.

It's a dark novel in which the burgeoning anger of the female protagonist is presented through her decision to opt out of her life of toil now that her twins have left home, while her husband and all those around her proceed to show their worst, most selfish sides in their effort to cope with her long-term dive under the duvet.

Sometimes women just let their families' bad behaviour wash over them, Townsend reflects.

"Some women allow themselves to be turned into a victim, a mix of martyr and brave little mother. Stronger people take advantage of those who are gentle in nature.

"It's hard for any woman to get to middle age," she continues. "You've always been reasonably attractive. You've been part of the life force and then life says to you, 'Why are you hanging around? You've had the children, you've fulfilled what human beings are here to do. Go away!'"

But Townsend never felt like going to bed and not getting up, despite her health crisis arriving at around the same time she hit middle age.

"No. I'm totally responsible for the complications of my diabetes," the down-to-earth author from Leicester asserts. "I thought I could get away with it but I couldn't. My blindness was caused by diabetic retinopathy [tiny blood vessels leaking across her retina due to high blood sugar levels]. The kidney transplant was also down to diabetes."

In 2009 her son Sean, also a writer, donated his kidney to her.

"He felt it more than I did. I'm used to having operations but he'd never been in hospital before. There was never any hesitation, though. I was thrilled he was going to give me his kidney, but also scared for him and truly appreciated it."

The transplant seems like a little scratch compared with the blindness that's engulfed her in the last 15 years.

"I can't read, I'm totally blind in the dark, I'm totally blind in sunlight or brightness. My good days are days like today in Leicester, when it's slash-your-wrist weather, can't decide whether to rain or not. That's good for me."

These days she dictates what she's writing, which is more difficult for the copytaker (again, her son Sean) than it is for her, she explains.

"I'm fanatical about my sentences. The rhythm of sentence is really important. The punctuation is crucial to get the rhythm right."

It's this precise rhythm that took her from hand-to-mouth single mother, who held down various jobs after her first husband left her for a young hippy, to best-selling author.

The postman's daughter from Leicester had been writing secretly since the age of 14, left school with no qualifications at 15, was married by 18 and had three children by the time she was 22.

The writing continued after she'd put the children to bed, and after the divorce from her first husband, but she never considered doing anything about it until she married her second husband, Colin Broadway, the father of her fourth child. She then joined a local writers' group and in 1979, the first of her many plays, Womberang, was produced.

Three years later, The Secret Diary Of Adrian Mole aged 13 3/4 was published, the first in a series that made her one of the top humorous writers and a millionaire.

The books have been adapted for radio, television and theatre, and have seen the eponymous hero go from teenage worrier in the early years to prostate cancer sufferer in The Prostrate Years (misspelling intended), with her most recent Mole novel being published in 2010.

The eight books in the series have sold more than eight million copies, been translated into 48 languages, and now there's a new 30th anniversary edition of the original.

"I just cannot believe it!" Townsend exclaims. "It seems to me that I've just blinked and it's 30 years ago."

She's thinking of writing a ninth instalment, which will probably find him blogging and tweeting, but in an incompetent way.

"He's a very kind, good person who feels his talents aren't appreciated, that he's underestimated by everybody and he's got a lot to contribute. An awful lot of people feel like that."

Townsend relies on other people more and more, she admits. She can't leave the house without someone and is wheelchair bound.

"I went to London twice after I was diagnosed with blindness and it was really dangerous and stupid of me, because I'd had no training. I didn't know how to properly use a stick. It was terrifying.

"I got on the train and was determined to show that I could be independent. I got off the train and started walking towards the track, where they'd put a barricade up. I barged in and put my foot through it. I was just stupid."

But there isn't an ounce of self-pity in her voice. Despite her disabilities, she has a busy life, with 10 grandchildren, who all live within four miles of her home, and another Adrian Mole book in her head.

"It will be about what the country's like to live in," she reveals. "He's had cancer and moved out to the countryside from the city, in his case to a pigsty.

"The next book may be to do with his children coming back. His mother's on Facebook, his father sits in his wheelchair all day with the ashtray welded to the arm. He could perhaps fall in love with the ambulance woman who takes him to hospital."

As our laughter subsides, Townsend reflects on her life with all its brickbats.

"I can't get over how lucky I am, I really can't. I have a wonderful husband, children I still see and grandchildren. And I've got no money worries unless people violently turn against Adrian Mole."

But surely, after 30 years, there's not much chance of that.

:: The Woman Who Went To Bed For A Year by Sue Townsend is published in hardback by Michael Joseph, priced £18.99. The 30th anniversary edition of The Secret Diary Of Adrian Mole aged 13 3/4 is published in paperback by Penguin, priced £7.99. Available now