If an adult has both low 'good' cholesterol and high 'bad' cholesterol, their risk of heart disease is higher than if they only had low 'good' cholesterol.

What we've found so far is that having both low HDL (the “good” cholesterol) and high LDL (the “bad” cholesterol) appears to be linked with a higher risk of heart disease compared to having low HDL alone [1]. Our analysis of the available research shows this pattern consistently across the evidence we’ve reviewed. We looked at 53 studies or assertions, and all of them support the idea that when both of these cholesterol markers are off—low HDL and high LDL—the risk for heart disease is greater than when only HDL is low [1]. No studies in our review contradicted this. This suggests the combination may be more concerning than low HDL by itself. HDL helps remove cholesterol from the arteries, while high LDL contributes to plaque buildup. When both are present—less cleanup and more buildup—the body may face greater strain over time [1]. But we’re only reporting what the evidence shows; we don’t know all the reasons why this pattern exists, and other factors like diet, activity, genetics, and inflammation may also play roles. Our current analysis shows the evidence leans toward higher risk with both imbalances. Still, we don’t have enough detail to say how much higher the risk is, or whether fixing one or both values will reduce it. We also can’t say whether this applies equally to everyone—our review doesn’t break down age, sex, or lifestyle differences. As we continue to analyze new data, our understanding may change. For now, what we can say is that the combination of low HDL and high LDL has been consistently linked with greater risk in the studies we’ve examined. Practical takeaway: If your cholesterol shows both low HDL and high LDL, it may signal a higher risk than low HDL alone—something worth discussing with your healthcare provider.