Deborah Knight was not yet 50 when the broadcast journalist received the shock news that she had contracted a painful and debilitating illness.

Like many Australians, the Sydney-based TV and radio presenter was vaguely aware of the threat of shingles, but before her diagnosis did not appreciate just how common the disease is.

"It started with intense pain in my lower back, followed by a rash with sensitive blisters on my face," she said.

"Shortly after these symptoms began, I saw my doctor who confirmed I had shingles.

"I live a really active lifestyle, so it was confronting to need my husband and son to help me stand up due to the pain."

Shingles is an infection caused by the reactivation of the same virus that causes chickenpox earlier in life - the varicella zoster virus.

About one in three Australians are expected to develop the disease in their lifetime, but a survey released for Shingles Awareness Week revealed only two in five thought they were likely, very likely or extremely likely to contract it.

More than one quarter said they did not know their risk, while 16 per cent believed they were not likely and 18 per cent only somewhat likely to develop shingles in their lifetime.

The study, commissioned by pharmaceutical company GlaxoSmithKline and conducted by Ipsos, surveyed 300 Australians between 50 and 79 years old.

A larger, global study commissioned by GSK of 3500 respondents, including 250 Australians, found almost nine in 10 underestimated their risk and more than one quarter believed only one in 100 people would develop shingles in their lifetime.

Professor Tony Cunningham, director of the Centre for Virus Research at The Westmead Institute for Medical Research, says the risk of shingles is particularly acute for people over the age of 50.

"If you've had chickenpox the virus can remain in your body, kept dormant by your immune system," he said.

"As you age, there is a decline in your immunity that can leave you susceptible to the reactivation of the virus, and if this occurs, reactivation of the virus leads to shingles."

A painful and often debilitating disease, shingles can materially reduce a person's quality of life.

"So being aware of the symptoms and not underestimating your risk is important," Prof Cunningham said.

"Discuss it with your family, particularly with older members of your family who are more at risk and may not be aware of shingles."

Ms Knight's familiar voice is back on the airwaves after being forced to take time off during her initial battle with the illness.

She encouraged all Australians over the age of 50 to talk to their doctor about their risk.

"Before I was diagnosed, I didn't know much about shingles and the impact it could have," she said.

"I'd thought it was a disease that affected people much older than me."