New study finds millions of people could have aggressive deadly disease without even knowing

Millions of people could have a deadly disease without even realising it, according to a recent study.

New research has revealed that over 15 million people from across the US, UK, Germany and France have a condition that they're completely unaware of.

The study, which was published in The Lancet Regional Health Europe, found that around 20 million people are suffering, with only 2.5 million having a diagnosis of the disease, while around three-quarters of those with the illness have no idea.

The health condition can progress through four stages, with most people only developing the first stage, often without being aware of it.

However, in some cases, it can develop and eventually lead to liver damage if not treated.

15 million people could be unaware that they have fatty liver disease (Getty Stock Photo)

Non-alcoholic fatty liver disease (NAFLD) - also known as metabolic dysfunction-associated steatotic liver disease (MASLD) - occurs in those whose liver contains over five per cent fat and who consume little to no alcohol, with excessive alcohol consumption being referred to as an alcohol-related fatty liver disease.

The first and less severe stage is known as 'simple fatty liver' and is a build-up of fat in the liver cells (via Healthline).

Meanwhile, 'metabolic dysfunction-associated steatohepatitis (MASH)' is a more serious form of the disease in which the liver is inflamed as a result of fat build-up.

Without treatment, the third stage - fibrosis - can occur, causing scar tissue around the liver. The most severe stage is cirrhosis, in which the liver tissue is gradually replaced with scar tissue, according to the Cleveland Clinic. This can lead to permanent liver failure and, in some cases, liver cancer.

The study has called for an increase in diagnosis rates, as Dr Jeffrey Lazarus, the lead author of the paper, said: "Undiagnosed MASH costs economies billions of pounds in lost productivity and poor health. Unless diagnosis rates are doubled, alongside similar increases in treatment and care, direct health costs alone are predicted to triple over the next 20 years."

An ultrasound scan can help diagnose fatty liver disease (Getty Stock Photo)

Meanwhile, Emmanouil Tsochatzis, a professor of hepatology at University College London, added: "More than 15 million people across the US and Europe have the deadliest form of fatty liver disease – and don't know it. Without faster diagnosis and access to treatment, the human and economic toll will skyrocket."

According to the NHS, you're at an increased risk of NAFLD if you:

• are obese or overweight
• have type 2 diabetes
• have a condition that impacts how your body uses insulin, such as polycystic ovary syndrome
• have an underactive thyroid
• have high blood pressure
• have high cholesterol
• have metabolic syndrome
• are over 50
• smoke

A blood test showing high levels of liver enzymes is often the first step to confirming a diagnosis.

Doctors may then order an ultrasound or CT scan, a biopsy or a FibroScan, which is a specialized ultrasound.