High blood pressure, defined here as 140/90 mmHg or higher, is the focus of the final chapter. It outlines how common hypertension has become and the main risk factors, including older age, genetics, obesity, physical inactivity and a high-salt diet. The chapter explains how raised blood pressure can affect fertility in both men and women, partly through reduced blood flow, and notes that some traditional blood pressure medicines are thought to cause erectile dysfunction while newer drugs appear to have neutral effects. Lifestyle changes are presented as the first-line treatment, with a reminder that metabolic health is an important part of preparing for a healthy pregnancy.