It was not until he felt a tingling sensation in his arm and took himself to hospital that he discovered the diagnosis was actually much worse — he had suffered a heart attack.
Eight weeks on, Mr Clark is gearing up to make his return to the council chambers, albeit a bit worse for wear and a few kilograms lighter.
"[I’m] maybe two or three weeks from being back at work.
"[I] still have low levels of energy and have lost about 12kg since the day of the operation," Mr Clark said.
"I’ve got really skinny legs now, skinny arms.
"I’ve lost a bit of muscle mass because I haven’t been doing too much exercising."
Mr Clark, aged in his early 70s, is an open book in detailing the life-changing medical event he lived through.
The options were simple: a lifetime of medication or open heart surgery which would also require a lifetime of medication.
Mr Clark opted for the latter, but had to wait a further six days due to being loaded with blood thinners on the back of his first hospital visit in Invercargill.
"People have told me the surgery is like being run over by a bus.
"I think that’s an understatement, but never mind," he said.
The recovery had been slow, but he was just taking it one day at a time.
Looking back, Mr Clark was frank about the extra stress he took on board after assuming office in 2022, and the potential role that played.
His usual routine of biking and running around five to six times a week went out the window as the workload began to mount.
"You get called out, you go to meetings at night time.
"You can easily start the job at 8 o’clock in the morning and finish at 10 o’clock at night.
"I’ve just got to learn to say ‘no’ to a few people. Or delegate a few more out.
"You’re not good to anybody if you’re in the grave."
Realistically, that is where Mr Clark could have ended up.
But getting a second chance at life has also given him a fresh perspective.
He said he was now more appreciative for what he had, and focused on what actually mattered.
"I don’t need to be the champion of every cause, because with that comes long hours at work and stress."
There have also been fresh perspectives from unexpected places.
Following his heart attack, people who had been through similar procedures reached out and shared their experience which gave the mayor some hope.
"A major majority have said ‘look, I’m fitter now than when I had the heart attack. It’s been really good for me’."
"I’ve got that to look forward to."
Mr Clark was elected mayor of Invercargill in 2022, beating his closest rival by almost 3000 votes.
He has been a vocal voice at the council table since first entering as a councillor in 2019 — a position he secured with the highest number of votes that year.
Known for backing the ratepayer and pushing for a new museum build, he has also netted his fair share of controversy.
He served as deputy mayor under Sir Tim Shadbolt, the pairs’ breakdown in communication well-documented.
In March last year, he drew criticism for saying the "n-word" a number of times during a television interview in which he defended his use of the word earlier that week.
During a speech in June last year at an anti-co-governance meeting, Mr Clark said he opposed having mana whenua representatives at the council.
Asked this week if he considered finishing up as mayor following the medical event, Mr Clark said he had unfinished business.
"I was always going to come back.
"I do not give up."
- LDR is local body journalism co-funded by RNZ and NZ On Air.
