<s>[INST] What is a dangerously high blood pressure – how high does it have to be before you have a stroke or a heart attack ? [/INST] Any degree of high blood pressure is associated with increased risk of stroke and heart attack, but the higher the pressure, the higher the risks.If blood pressure is persistently 140/90 and greater, then some form of treatment is required, although in the first instance this might be adjustments to lifestyle, such as diet and exercise.However, if the blood pressure is repeatedly greater than 160/110, then there is usually a need to begin drug treatment immediately, rather than relying on lifestyle changes alone.Sustained blood pressures of over 200/120 are considered potentially dangerous and if associated with for example visual trouble or heart failure they require emergency treatment. Source: International Society of Hypertension. Link: https://ish-world.com/faq/. Field: Cardiovascular. Disease: Hypertension </s>