Heart disease starts way earlier than we think — like in childhood — and builds up quietly for years without symptoms, long before doctors can diagnose it.

What we've found so far is that heart disease may begin in childhood and develop silently over time. The evidence we've reviewed leans toward the idea that this process starts earlier than most people realize and progresses without obvious symptoms for years [1]. Our analysis of the available research shows that the buildup linked to heart disease can start as early as childhood. This means changes in the body—like the gradual accumulation of plaque in arteries—may be happening long before any signs appear or a doctor makes a diagnosis [1]. What we’re seeing suggests that heart health in adulthood could be influenced by what happens decades earlier, even in youth. However, the number of assertions we’ve reviewed is very limited—just one so far. That means our current understanding is based on a narrow foundation. While this single assertion points toward early onset and silent progression, we don’t yet have enough evidence to know how consistently this pattern holds across different people or what factors might speed it up or slow it down. We also can’t say how much childhood changes directly impact later risk, because the evidence doesn’t provide that detail. Our analysis remains incomplete, and as we review more studies, our understanding may shift. For now, what this could mean is that habits early in life—like eating nutritious foods, staying active, and avoiding tobacco—might play a bigger role in long-term heart health than we typically assume. But we’re still gathering and analyzing the data to better understand the full picture. Practical takeaway: Even if you feel fine, what you do now—and what kids do today—might matter more for heart health than we think, but we’re still learning exactly how much and why.