A blood pressure of <120 mmHg systolic and <80 mmHg diastolic at age 40 is considered normal. The normal range of blood pressure in adults is systolic blood pressure <120mmHg and diastolic blood pressure <80mmHg. systolic blood pressure ≥140mmHg, and/or diastolic blood pressure ≥90mmHg is defined as hypertension. 40 years old belongs to middle-aged people, for middle-aged people, hypertension often manifests as increased diastolic blood pressure, systolic blood pressure may or may not be increased. Increased diastolic blood pressure alone is common in obese men. It is recommended to have a low-fat, low-salt diet, eat more fresh vegetables and fruits, increase physical activity, lose weight, maintain a good state of mind, avoid staying up late, and quit smoking and limit alcohol.