NFL legend Dan Marino reveals his fatty liver disease diagnosis: Doctor explains what is MASH and how to manage it

NFL legend Dan Marino has revealed he was diagnosed with MASH, a serious liver condition, and shared how mild fatigue and reduced exercise led to the diagnosis.

Dan Marino is one of football's most iconic figures. Known for his extraordinary career with the Miami Dolphins, Marino shocked many when he revealed that he was quietly battling a serious liver condition. The Hall of Fame quarterback recently opened up to PEOPLE, sharing that he was first diagnosed with metabolic dysfunction-associated steatohepatitis (MASH) during a routine checkup back in 2007.

Dan Marino shares his journey managing MASH through diet and exercise.(Instagram | Dan Marino)

Looking back, Marino recalls only a few subtle signs. "I was a little fatigued," he says. "I wasn’t really working out as much as I should — because I used to work out when I played all the time and I kind of got away from that a little bit. Those are the things I kind of noticed. Then they told me I had a fatty liver. I had MASH.”

At the time, he only felt mild fatigue and had noticed he was not exercising as much. What doctors found, however, was fat buildup in his liver. If left untreated, this condition can progress into cirrhosis or liver cancer.

Dan Marino opens up about his liver condition

Dan Marino, now 64, explained that the news came as a surprise back then. He did not have severe symptoms, just some fatigue and less exercise compared to his playing days. Doctors explained that MASH, once called nonalcoholic fatty liver disease, is more common than many realize and can progress silently. With the right lifestyle changes, though, it can be managed and even reversed. Since then, Marino has made health a priority, embracing regular exercise like biking and walking, keeping a close eye on his diet, and maintaining a healthy weight. His journey reminds us that early detection can make all the difference.

MASH is a type of liver disease that develops when too much fat builds up in the liver, leading to chronic inflammation. Over time, this can scar the liver and increase the risk of cirrhosis and even liver cancer. “Unlike alcohol-related liver disease, MASH occurs in people who do not drink heavily, which makes it particularly concerning because it often goes unnoticed. It is part of a larger group of liver diseases called MASLD (metabolic dysfunction-associated steatotic liver disease) and is often linked to obesity, diabetes, and high cholesterol,” Dr Swapnil Sharma, Chief Surgeon, Liver Transplant and Hepatobiliary Surgery, tells Health Shots.

Symptoms to watch out for

One of the biggest challenges with MASH is that it often develops silently. Many people show no symptoms until significant damage has already been done. When symptoms do appear, they may include:

• Persistent fatigue
• Discomfort or pain in the upper right abdomen
• Unexplained weight loss or muscle weakness
• Swelling in the belly or legs
• Jaundice (yellowing of the eyes and skin)

Since MASH symptoms can take years to appear, routine checkups are crucial, especially for people with risk factors like obesity or diabetes.

Fatigue throughout the day is sign of MASH. (Shutterstock)

Causes and risk factors

The exact cause of MASH is not fully understood. “While fat buildup in the liver is the starting point, not everyone with fatty liver goes on to develop MASH. Genetic factors, environmental triggers, and metabolic issues may all play a role,” says Dr Sharma. Key risk factors include:

• Obesity or being overweight
• Insulin resistance and type 2 diabetes
• High blood pressure
• High cholesterol or triglycerides
• Metabolic syndrome

Interestingly, even people who are not overweight can develop MASH if they have other risk factors such as high cholesterol or high blood pressure.

How is MASH diagnosed?

Doctors usually begin with blood tests to look for liver abnormalities, followed by imaging tests like ultrasounds, CT scans, or MRIs to detect fat buildup. In some cases, a liver biopsy, where a small tissue sample is taken, is the only way to confirm MASH and measure the extent of liver damage.

Treatment and management

Dr Sharma says there is currently no specific medication to cure MASH, but lifestyle changes are an important part of the treatment. Doctors recommend:

• Maintaining a healthy weight (even a 3–10 percent weight loss can help)
• Controlling blood sugar and cholesterol levels
• Exercising regularly
• Reducing or avoiding alcohol
• Following a balanced diet rich in whole foods

These steps can not only slow the disease but, in some cases, reverse the damage.