When I was six, I embarrassed a boy in class by putting my hand up and telling the teacher he’d wet himself. He sat two rows behind me but I’d smelled it, intensely.

He was so upset that my grandmother was called into school. When we got home, she warned: “Never use your sense of smell for that again.” She explained that I, like her, had hereditary hyperosmia – a heightened genetic predisposition to detecting odours, meaning I’m a super-smeller.

Where others use sight, I use my sense of smell. Disinfectants make me sick and perfumes overwhelm me. I used to apply a little lavender balm under my nose to help cope with unpleasant odours.

At 16, I met my husband, Les. We both pursued medical careers, he as a consultant anaesthetist and me as a nurse. We married, moved to Yorkshire, then Greater Manchester, and had three sons.

On a hospital shift early in my career, I remember being struck by the smell of a patient. I later learned that she had diabetes and what I smelled was raised ketones – a chemical produced by the liver, which builds up when diabetics are unwell. Smelling illnesses on patients became a pattern, but I knew doctors wouldn’t accept my diagnoses, so I stayed quiet.

In 1982, before Les’s 32nd birthday, I noticed a musky, dank odour on him – he knew about my heightened sense of smell. I thought it might be the unprocessed air of the operating theatres he worked in and told him to shower more. That caused arguments.

Twelve years later, in 1994, he was diagnosed with Parkinson’s disease. The damage was irreversible by the time we had endured the usual slow journey to diagnosis. We instantly made the connection to the smell, but it wasn’t until the last months of his life, more than 20 years later, that we discovered I could detect it in others, too. By then we were living in Perth, Scotland, and walked into a local Parkinson’s UK support group. My chin bobbed up – a tic when strong smells hit me. It was overwhelming. Over dinner I told Les: “Those people smelled the same as you.”

We felt a responsibility to do something. We attended a lecture by Prof Tilo Kunath, a regenerative neurobiologist. I asked: “Why is the smell of Parkinson’s not being used for early diagnosis?” He didn’t have an answer and we left disappointed, but Les was sure that wasn’t the end.

Four months later, Prof Kunath called our home. He had found me after relaying my query to a research colleague, who told him: “You must find that woman.” We began to work as a team to prove my theory.

Les and I should have been enjoying retirement, but Parkinson’s had stolen our lives. We became determined that others wouldn’t suffer the same way. When Les died in June 2015, he made me promise I’d carry on. I spent time in labs, smelling sufferers’ T-shirts and swabs for sebum – the skin oil we all produce, which changes with the onset of Parkinson’s. I could detect whether the person had the disease with 95% accuracy. I was surprised.

In September this year, our research team at the University of Manchester published a breakthrough: a three-minute test that can detect the disease by running a cotton bud along someone’s neck. I felt very emotional. We were a step closer to early diagnosis and treatment.

I’ve become known as “the woman who can smell Parkinson’s” and have delivered lectures on my work. I’m working with people in California, detecting cancers, and in Tanzania, to locate the smell of tuberculosis. Smell is an underestimated sense. We accept a whisky or perfume nose but not a medical one. A professor once told me, “You realise you’re closer to a dog than a human?” I took it as a compliment.

I’m an advocate for both the World Parkinson Coalition and PD Avengers, a global alliance to end the disease. I never imagined, at 72, this would be my life’s work. I constantly think about how I lost my Les, but also how, in those last six weeks we had together, we set his legacy in motion.

• As told to Deborah Linton. Comments on this piece are premoderated to ensure the discussion remains on the topics raised by the article. Please be aware that there may be a short delay in comments appearing on the site.

Do you have an experience to share? Email experience@theguardian.com