HOWARD Springs grandmother Suzanne Cavanagh has a rare immune system disease, which until four years ago, was slowly robbing her left arm of its strength and causing painful cramping.

Her left hand deteriorated so badly Ms Cavanagh could no longer type and struggled to pick things up.

“There was no upward strength in my hand,” she said.

After meeting with a specialist in 2014, Ms Cavanagh was diagnosed with multifocal motor neuropathy.

“It’s an immune system disease, and what it means is that my immune system thinks there is something wrong, but there isn’t,” she said.

Ms Cavanagh receives immunoglobulin infusions every six weeks; something made possible by the generosity of blood donors.

The disease is regressive, but since she started getting the infusions, Ms Cavanagh’s condition has noticeably improved.

In the past four years, Ms Cavanagh has got the mobility back in her hands and no longer gets cramps.

Blood Service spokesman Shaun Inguanzo urged Territorians to roll up their sleeves and give blood to improve the lives of Australians such as Ms Cavanagh.

Supplies of O-negative have reached a critical low.

People with O-negative blood are universal donors.

“The issue we are experiencing is a drop in numbers for cold and flu symptoms,” Mr Inguanzo said.

“In the colder states, people are hit harder.”

The Blood Service is looking for about 80 O-negative donors in and around Darwin to help fill the gaps this month.

Those donations could save the lives of 240 patients.

He said people who lived in and around RAAF Base Tindal, and had potentially dangerous PFAS chemicals in their blood could still donate.

“There is currently no evidence that PFAS levels in blood donations, which are a small percentage of one’s total blood volume, have had any health impacts on … blood transfusions,” he said.