A surprisingly common liver disease affects millions in the US. What to know, according to a doctor

(CNN) — A health condition many people have never heard of has become one of the most common liver diseases in the United States.

Metabolic dysfunction–associated steatotic liver disease, or MASLD, often develops quietly, so many people do not realize they have it until it is more advanced and signs show up in blood tests or ultrasounds. Even then, the disease can be hard to detect.

What is MASLD, and why is it becoming so common? How is it diagnosed if most people do not notice the symptoms? Who is most at risk? Can the condition be slowed or reversed, and what treatments exist? And what steps can people take now to protect their liver health?

To guide us through these questions, I spoke with CNN wellness expert Dr. Leana Wen. She is an emergency physician and adjunct associate profes