A charity has described the number of winter deaths in Scotland as “staggering”, with statistics showing an increase to the highest level in 18 years.

Figures released today by the National Records of Scotland (NRS) reveal a total of 23,137 deaths were registered across the country from December 2017 to March 2018 – up from 20,946 in 2016-2017.

It is the largest number since 23,379 deaths were registered in winter 1999-2000.

The national charity for older people, Age Scotland, has called for more to be done to help those most at risk from becoming ill.

Age Scotland’s head of policy and communications Adam Stachura said: “These figures are staggering and a real shock to the system.

“The large increase in deaths due to flu and pneumonia should be setting alarm bells ringing.

“We know that during winter months the homes of many older people are insufficiently heated as a result of high fuel costs and poor heating systems, and can lead to a greater risk of ill health and even death.

“This year, energy companies hiked their fuel prices between 4% and 9%, which could add hundreds more pounds to a person’s heating bills especially during long, cold winters like last year.”

There are a higher number of deaths in winter than at any other time of year, although there has been a downward trend since 1951-1952.

Over the past five years there has been an increase, however, with some unusually large rises.

There is no single cause of “additional” deaths in winter but they include respiratory system diseases (such as pneumonia and chronic obstructive pulmonary disease),  circulatory system diseases (such as coronary heart disease and stroke), Alzheimer’s disease, dementia, Parkinson’s disease and other degenerative conditions.

Very few are caused by hypothermia and only a small proportion directly by influenza.

NRS chief executive Anne Slater said:  “There are always more deaths in the winter in Scotland than in any other season but the long-term trend since the early 1950s has clearly been downward.

“However, the average value for the latest five years (which smooths out much of the year-to-year fluctuation) is now above the level that had applied since the early 2000s.”

The Scottish Government has urged all eligible adults to get a free flu vaccination ahead of the coming winter.

A Scottish Government spokesperson said: “Reducing health inequalities is one of the biggest challenges we face and we’ve focused on addressing the underlying causes – ending poverty, fair wages, supporting families, and improving our physical and social environments.

“This includes driving investment in affordable housing, continuing our commitment to free prescriptions, concessionary travel and free personal care, and making homes warmer and cheaper to heat.

“We are on track to deliver our 2016 Programme for Government commitment to make £500m available by  2021 to tackle fuel poverty and improve energy efficiency.”

Scotland’s Chief Medical Officer Dr Catherine Calderwood said: “Every year in Scotland, around two-thirds of people who get severe flu and need intensive care treatment have a health condition such as chronic lung or heart disease.

“Flu vaccines are available free to all eligible adults, including everybody aged 65 and older, and protects against a number of different flu strains.

“Vaccination remains our best defence against flu, and I urge people to take up the offer of a free vaccine.”

Professor Derek Bell, president of the Royal College of Physicians of Edinburgh, said: “We know that an excess of deaths were reported last winter compared to the seasonal average, in part related to influenza and other respiratory infections.

“As such we continue to encourage all at-risk patient groups – and indeed health and care staff – to have their annual flu vaccination.

“It is also vital to have effective winter planning for all acute and emergency services.”

Miles Briggs, Scottish Conservative shadow health spokesman, said: “This is a stark warning to the SNP that they must prepare the NHS properly for winter and ensure that all our elderly and vulnerable patients get the recommended flu vaccination.

“As these worrying statistics continue to emerge, it is quite clear that the SNP cannot be trusted to run our health service.”

Scottish Labour’s health spokeswoman Monica Lennon MSP said many of the winter deaths are preventable.

“Instead of planning ahead, SNP ministers have lost credibility by failing to buy enough enhanced flu vaccine for this winter,” she said.

“Lives are at stake and it’s over to Nicola Sturgeon and her health secretary to reassure the people of Scotland that they are doing everything possible to equip our NHS to reduce preventable deaths this winter.”

Scottish Liberal Democrat health spokesman Alex Cole-Hamilton MSP said: “While our NHS staff have done fantastic work in ensuring that the long-term winter mortality rate is in decline, last year’s steep rise in winter deaths is a cause for concern.

“There are staff shortages across health and social care and this is clearly having an impact.

“The health secretary must set out what lessons have been learned from these tragic deaths and what changes have been made to ensure that our NHS is ready for another cold winter.”