Alice Dogruyol, a 49-year-old publicist from London, was diagnosed with type 1 diabetes after persistent bad breath signalled a life-threatening medical complication. Her boyfriend told her her breath smelled like nail varnish remover, leaving a sour taste in her mouth. She brushed her teeth obsessively, drank water, and used breath sprays, but nothing eliminated the heavy odour.
It took a year for Dogruyol to realize her bad breath was not caused by poor oral hygiene. She also suffered from recurrent fungal infections and rapid weight loss before learning she had diabetic ketoacidosis, a severe complication of type 1 diabetes. The condition occurs when high blood sugar and a lack of insulin cause the body to rapidly burn fat for energy, producing chemicals known as ketones.
Ketones produce a distinctive acetone or pear-drop smell that is emitted through breath and sweat. Without urgent medical treatment, diabetic ketoacidosis can lead to unconsciousness, coma, and death. Doctors later informed Dogruyol that she was just one week away from falling into a coma.
Misdiagnosis and Type 1 Diabetes Symptoms
Dogruyol had previously been diagnosed with type 2 diabetes in 2019, a misdiagnosis that delayed her access to correct treatment. Just before Christmas in 2020, after several attempts to resolve her symptoms, a nurse suggested she be tested for type 1 diabetes. She received her diagnosis in January 2021 and began daily insulin treatment, which caused the bad breath to disappear.
The distinction between the two conditions is crucial for patient care. People with type 1 diabetes can no longer produce insulin and require daily injections to survive. A study by researchers at the University of Exeter found that 38 per cent of adults with type 1 diabetes diagnosed after age 30 were initially treated for type 2 diabetes and denied insulin.
People with type 2 diabetes still make insulin, but their bodies struggle to use it properly, allowing many to initially control the condition with diet, exercise, and medication. Type 1 diabetes occurs when the immune system mistakenly attacks insulin-producing cells in the pancreas. Without insulin, blood sugar levels can rise to dangerous levels.
Once viewed primarily as a childhood illness, type 1 diabetes can develop at any age, and nearly half of all cases are now diagnosed in adulthood. The cause of the rise in adult type 1 diabetes is unclear, though potential factors include low vitamin D levels from reduced outdoor play and less exposure to germs due to overparenting.
Symptoms of type 1 and type 2 diabetes can be similar, including excessive thirst, frequent urination, tiredness, and sudden weight loss. However, type 2 diabetes often develops over months or years, whereas type 1 diabetes can strike within days or weeks. Because adults with high blood sugar are often assumed to have type 2 diabetes, initial misdiagnoses remain common.
Body Odour as a Disease Indicator
Dogruyol's experience highlights how changes in body odour across breath, skin, sweat, or urine can serve as early warning signs of illness. Dr Dean Eggitt, a GP at The Oakwood Surgery in Doncaster, explained that diseases alter the chemical composition of the body, which then excretes these unique chemicals through sweating, breathing, and going to the toilet.
Dr Eggitt stressed that bad breath is usually caused by hygiene habits, strongly flavoured foods, dental issues, or common infections like tonsillitis. However, he noted that context is key for diagnosis. He stated that if someone is generally unwell and a new smell accompanies new symptoms, it should be treated as a red flag.
Advanced liver failure, or cirrhosis, causes a distinct musty, sweet, or sulphur-like body odour when the liver loses its ability to filter toxins from the bloodstream. Sulphur-containing compounds build up in the blood and are exhaled through the lungs. Dr Eggitt described the odour as smelling like an old granny's house that is stale and mouldy, typically appearing alongside jaundice, confusion, or abdominal swelling.
Chronic kidney disease, which affects about one in ten adults in the UK, can cause an ammonia-like smell known as uraemic breath. This occurs when failing kidneys struggle to filter toxins, causing a dangerous build-up of waste in the bloodstream and saliva.
Smell Analysis in Clinical Diagnosis
While some illness odours are obvious, others are too subtle for most people to notice. In 2015, retired nurse Joy Milne made headlines after proving she could smell Parkinson's disease due to hyperosmia, a rare condition that gives her a heightened sense of smell. She noticed a musty odour on her husband 12 years before his diagnosis and correctly identified Parkinson's from patient T-shirts, inspiring a new skin swab test for chemical biomarkers.
Researchers are also developing an electronic nose to capture and analyse specific chemical gases in clinical settings to detect diseases such as cancer. Dr Eggitt noted that these smells originate from chemicals that continuously release gases based on what is happening to the body.
Professor Victoria Tzortziou Brown, of the Royal College of GPs, said changes in body odour or breath provide clinical clues but are very unlikely to be used in isolation to diagnose a condition. She explained that smell is only one part of a wider clinical assessment that includes patient symptoms, medical history, physical examination, and medical tests.
Reflecting on her ordeal, Dogruyol urged people not to ignore changes in body smell. She stated that instead of masking the bad odour, she wished she had taken it seriously as a warning sign, adding that knowing the breath change signified illness might have led her to push for a diagnosis sooner.
