Endothelial dysfunction refers to a condition where the endothelium, a thin layer of cells lining blood vessels, does not function properly. This can lead to reduced production of substances that help regulate blood flow and maintain vascular health, such as nitric oxide. Factors like high blood pressure, smoking, and diabetes can contribute to this dysfunction, increasing the risk of cardiovascular diseases. When endothelial dysfunction occurs, it can result in inflammation and the formation of plaques in the arteries, a process known as atherosclerosis. This can restrict blood flow and lead to serious health issues, including heart attacks and strokes. Maintaining a healthy lifestyle can help prevent or improve endothelial dysfunction.