A "wonderful" and "incredibly selfless" mum-of-three died of sudden cardiac arrest, an inquest has heard.

Lisa Parfitt, 49, was found lifeless in her home in Tunbridge Wells after her sister, Sally Boorman, raised concerns for her welfare with police.

Giving evidence at Canterbury Coroners' Court today, she described how she raised the alarm on January 2 when she realised her sister, who suffered rheumatoid arthritis, had failed to check her Whatsapp messages for two days.

Ms Parfitt, who worked as an insurance clerk for Axa, had spent Christmas at her sister's home just days before and despite her health problems had appeared "on very good form".

"She as well, she was happy," Mrs Boorman said.

"She had just become a grandma and had been looking forward to seeing her grandson."

After realising that Ms Parfitt's 23-year-old son Samuel had also posted on Facebook, asking if anyone had heard from his mother, she became worried and decided to check on her sister.

She raced to her home in Commercial Road and phoned police, who found Ms Parfitt's body after forcing entry to the property.

The inquest heard how Ms Parfitt, who was divorced and also mother to Louis, 28 and Lily, 19, was last heard from when she phoned in sick to work on New Year's Eve.

Also giving evidence, pathologist Dr Ann Fleming said that although post-mortem reports found signs of pulmonary oedema - the accumulation of fluid in the lungs - and kidney scarring, there was "no obvious cause of death".

Adding that Ms Parfitt, who had been taking medication for her arthritis, had been "very thin" and at the time of her death weighed just 37 kilos, she said: "This is one of the 10% of cases where you do a full post-mortem and do not find a cause of death.

"She was incredibly selfless, she was always thinking of other people" - Samuel Parfitt

"Her heart must have stopped suddenly because of the pulmonary edema."

Speaking after the inquest, Samuel Parfitt described his mother, who was born in London but spent most of her life in Tunbridge Wells, as a "bit of a party animal" who was "kind to a fault" and had inspired him to start volunteering with a homeless charity.

"We were very close. I saw her every day and she had all the time in the world for her children," he said.

"She was incredibly selfless, she was always thinking of other people.

"She only wanted the best for everybody. If I was having a bad day, or if I was not feeling well, the first person I would call would be my mum.

"A lot of people have a mum and son relationship. But she was a friend. I think she made everyone she had ever met a nicer, kinder person.

"She was a one-of-a-kind, beautiful, wonderful person. I don't think I will ever meet someone quite like my mum."

Recording a verdict, assistant coroner James Dillon attributed Ms Parfitt's death to a natural cause by sudden cardiac arrest, with renal damage and electrolyte disorder also a factor.

"There's no evidence that suggests anything more than that she passed away in her home," he said.

"It only remains for me to offer, from all of us in the Coroner's service, condolences to you all for the loss of Lisa at the age of only 49."