How do you know when you've reached middle age? Tell-tale signs include opting for elasticated waists and Velcro-fastening slippers, says best-selling author Sue Townsend.

She tells Hannah Stephenson about why it doesn't have to be all downhill from 40.

There are few of us who don't fear the onset of middle age, as we start to become more irritable, impatient and sensitive to noise.

So says best-selling author Sue Townsend, creator of the Adrian Mole series, who herself hit middle age some time ago and, after an initial period of depression, has slowly but surely worked her way towards acceptance that she is no longer the bright young thing that she once was.

Townsend, 57, whose book The Public Confessions Of A Middle-Aged Woman covers a range of subjects you consider in middle age, from slugs and hosepipe bans to Agas, retirement and heatwaves, reckons that middle age happens from around 45 onwards.

"Middle age is depressing at first. People do go into a decline when they realise. There's often a fresh crop of young women behind you."

Interests change in middle age, she says. Gardening becomes exciting, clothes become comfortable and thoughts of holidays veer towards cruises rather than trekking.

How did she know when she'd reached middle age?

"It was going up the stairs," she recalls. "I remember I was wearing a dressing gown and the cord was trailing on the stairs and I became aware of my posture. I let everything slump. It was a physical feeling."

Townsend, who is registered blind due to a condition called diabetic retinopathy and cataracts, is also now confined to a wheelchair because she has Charcot's joint, a type of degenerative arthritis - but she retains her sharp sense of humour.

Her husband, canoe builder Colin Broadway, chooses her lipsticks and paints her nails, while her daughters help her choose her wardrobe. Appearance in middle age is still important, she says. And she has firm views on what is and what is not acceptable for the more mature woman.

"I don't think middle-aged women can have long hair unless they have plastic surgery every six months.

"As for make-up, there is a fine line between looking good or ending up as mutton dressed as lamb. It may just be down to the shade of lipstick.

"I do my own make-up but my husband does what we call a 'Coco check' to make sure I don't go out looking like Coco the Clown or Bette Davis."

Your love life doesn't have to take a dive when you hit middle age, she says.

"Sex in middle age is a tricky one. You are self conscious in your middle-aged body, so you have to be clever with lighting. You need mood lighting, never a bright overhead ceiling light, and something flattering to wear. Alcohol helps.

"In the bedroom you need to be more patient with your partner. Men also get self conscious. And try not to scurry into the bathroom as though you have some skin disease you are trying to hide."

But there are also advantages in ageing, she notes.

"Middle age has a culture of narrow mindedness and caution, but it is possible to be middle aged and be reckless and brave. Until recently I've jumped into various projects without looking.

"I've also become much braver about what I say. I've always been very opinionated but I've been quiet about my opinions. Now I'm much braver. And I have the facility now to blank out anything I don't want to hear."

Middle age also allows you to do things that would never have been acceptable when you were younger, she adds.

"It can be a happy time because you are given permission to slow down occasionally when you want to and even go to sleep in the afternoon."

* Public Confessions Of A Middle-Aged Woman, by Sue Townsend, is published in paperback by Penguin, price £6.99