Cardiovascular risk develops when blood vessels are repeatedly stressed over time. Harmful processes gradually build up, including plaque formation, vessel inflammation and changes in blood flow. This is why risk is described as a probability over years, not a single event.

How risk is calculated: clinicians use validated tools such as the ASCVD risk calculator or the Framingham risk score. These combine your cholesterol levels, blood pressure, blood sugar, smoking status, age and sex to estimate the percentage chance of a heart attack or stroke over the next 10 years. A score below 5% is generally considered low, 5–20% is intermediate, and above 20% is high, though exact cut-offs vary by tool and should always be interpreted by a healthcare professional.

What drives the process: high LDL ("bad") cholesterol can enter vessel walls; high blood pressure and high blood sugar can damage the vessel lining, making plaque more likely to form. Chronic inflammation can accelerate these changes.

Your gut microbiome may also play a role. Some gut bacteria produce metabolites that affect inflammation and how your liver processes cholesterol, while others help maintain gut barrier health, which can influence immune activity linked to cardiovascular disease.