Two years ago, Allison Grainger went to her doctor after feeling constant fatigue and nausea. A quick trip to the grocery store would exhaust her.

The lethargy was so intense, the 26-year-old quit her job working as a spa concierge.

Her primary care doctor sent her to a specialist, who found abnormal levels on her liver function tests. A liver biopsy later showed she had nonalcoholic steatohepatitis, or NASH, a more severe form of nonalcoholic fatty liver disease that occurs when there’s too much fat in the liver.

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“I was very shocked,” she said. “At the time I was devastated.”

Hispanic Americans like Grainger disproportionately suffer from the disease and its more severe form NASH, with estimates showing NASH rates highest in this group.

Meanwhile, nonalcoholic fatty liver disease affects between a quarter to a third of the U.S. population, according to estimates, and rates are rising in adults in their 20s and children. It's also the leading cause for liver transplants in women, research shows.

Experts say patients often lack symptoms, and raising awareness is essential to help them get the care they need to manage progression.

What is nonalcoholic fatty liver disease and what are the symptoms?

Nonalcoholic fatty liver disease, or NAFLD, refers to a group of conditions in which too much fat is deposited in the liver but no inflammation or damage occurs to the organ. 

Some fat is normal in the liver, but abnormal levels are a concern. The liver, which filters blood in the body and breaks down substances such as alcohol and drugs, produces bile, a fluid that helps digest fats eliminate wastes.

Nonalcoholic steatohepatitis, or NASH, is a form of the disease in which swelling occurs in the liver, caused by the buildup of fat. The inflammation can then lead to fibrosis, which is scarring and damage to the liver.

Left untreated, NASH can lead to cirrhosis, which is severe scarring and permanent damage of the liver that can lead to liver failure.

NAFL and NASH are considered "silent diseases" and usually don't come with symptoms. But if they do, advanced forms can cause fatigue, aching in the upper right abdomen, yellowing of the skin and eyes known as jaundice, and unexplained weight loss.

Cases are rising among Hispanic population 

Among patients with nonalcoholic fatty liver disease, cases of NASH are highest in Hispanic Americans, according to an analysis of 10 studies published in the journal of Clinical Gastroenterology and Hepatology.

“There definitely is some disparity around diagnosis, around awareness and around progression," said Dr. Nadege Gunn, a gastroenterologist and hepatologist at the University of Texas Impact Research Institute. She noted Hispanic women especially are seeing disproportionate rates.

“It's just such a quiet, just nondescript condition that people fall into finding out about,” Gunn added. “When there's no access or limited resources to diagnose in communities of color, you're certainly going to find that there’s some differences as far as linkage to care.”

Gunn and other professionals say genetic predispositions and diet could be behind the disparity.

Early diagnosis is key to managing the disease, said Dr. Brian Lee, a liver doctor at the University of Southern California.

“It's important not to ignore factors that aren't related to biology and genetics,” he said, noting higher rates of uninsured Hispanic and Latino people compared to white people. Being uninsured or receiving public insurance, he said, “influences your rate of developing liver disease progression” because these patients often lack access to preventative care to catch the problem.

What's behind the increase in kids?

NAFLD is the most common form of liver disease in children, according to the Children's Liver Disease Foundation. Estimates show between 5% to 10% of American children have NAFLD, of which 20% to 50% have the NASH form, the National Institutes of Health says. 

Researchers are studying why cases are rising. Children and young people are at higher risk if they are overweight, obese, have Type 2 diabetes or insulin resistance, a poor diet and lack of exercise.

NAFLD is most common in Hispanic and Asian American children, followed by white children. It's less common in Black children, according to the NIH.  

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Risk factors for nonalcoholic fatty liver disease 

Having diabetes, being overweight or obese and having high triglycerides are risk factors for nonalcoholic fatty liver disease. Research suggests that the disease is present in up to two thirds of people with diabetes, 75% of overweight people and more than 90% of people who have severe obesity, according to the NIH.

Often, patients who come to Gunn and end up with a NASH diagnosis have had diabetes or been overweight for years. 

“But no one ever told them to get their liver checked,” she said. That’s why the physician runs awareness programs for doctors and communities in her area, including holding a “NASH Bash” with free screenings a few times a year.

Treatment for nonalcoholic fatty liver disease

While there’s no current medication to treat the disease, lifestyle changes such as weight loss and better nutrition can help manage and improve the condition long term.

Lee said the biggest problem is diagnosing the condition early enough. Regular check-ups are essential to evaluate and control those risk factors, he said. Early detection and lifestyle changes can help reverse some damage.

"There are options for the liver to improve and actually regenerate," Lee said. "But if you're too late, then really the only option, we think, is a liver transplant.”

Before Grainger became pregnant, she was enrolled in the first clinical trial, led by Gunn. Grainger, who had prediabetes prior to getting the NASH diagnosis and now diabetes, wears a continuous glucose monitor to help keep track of her blood sugars.

“I wish I would have known all this information because I was kind of clueless whenever I found out. I knew nothing about it,” she said. “If you get yourself checked out, maybe you can catch it faster than I caught it.”

Reach Nada Hassanein at nhassanein@usatoday.com or on Twitter @nhassanein_.

This article originally appeared on USA TODAY: A 'quiet' liver disease is on the rise in kids and Hispanic people: What you need to know