The number of older people falling unwell with vomiting and diarrhoea are at their highest for a decade.

Cases of norovirus, which has been described as a 'really unpleasant illness to catch' by one NHS professor, are 66% higher than average for the time of year according to confirmed lab reports - with the biggest increase in illness among people aged 65 and over.

While high numbers of cases in this age group are often expected in late winter, says the UK Health Security Agency, the numbers of older people currently unwell with the virus haven't been found at current levels in well over a decade.

Common symptoms of norovirus include feeling and being sick, diarrhoea and stomach cramps. People may also suffer headaches, a high temperature and aching arms and legs. Norovirus is highly infectious and is easily and quickly spread through contact with someone who has the infection or contaminated surfaces.

While most people will make a full recovery in two to three days, very young children, the elderly or those with weakened immune systems are at an increased risk of complications.

The majority of tested and confirmed outbreaks - currently numbering hundreds each week - are in care home settings but outbreaks have also leapt in hospitals and schools say health officials, who want to remind people that good hand hygiene is key to halting any spread.

Dr Lesley Larkin from the Gastrointestinal Infections and Food Safety (One Health) Division at UKHSA, said: "Norovirus levels are currently the highest we have seen at this time of year in over a decade. Most reported cases are in the over 65s and we’re also seeing a rise in reported outbreaks, particularly in care home settings.

"Please stay at home if you are experiencing norovirus symptoms and do not return to work (particularly if you work with vulnerable people or food) or send sick children to school or nursery until 48 hours after symptoms have cleared. If you have a loved one in a care home or hospital, please avoid visiting until 48 hours after symptoms have cleared."

Alcohol gels, advises the UKHSA, will not kill off norovirus which is best tackled with soap and warm water.

NHS Medical Director, Professor Sir Stephen Powis, said: "The number of people in hospitals with norovirus has risen significantly in line with what we are seeing in the community and in care homes – it is a really unpleasant illness to catch, but for the vast majority of people it will usually pass in a couple of days, and self-treating at home is the best way to help yourself and avoid putting others at risk."