How does an unhealthy lifestyle impact the circulatory system?
There are a number of ways in which a lifestyle could be said to be unhealthy. Probably some of the first ways that come to mind are poor diet and lack of exercise, but things like smoking and caffeine overuse can also have an impact on circulation. And of course there are other ways in which a lifestyle could be considered unhealthy that do not directly impact a person's circulatory system, such as making poor social or behavioral choices, driving recklessly, or shoplifting. It makes the most sense to contextualize the answer in terms of the choices that do directly impact circulation.
A poor diet that includes excessive sodium intake without a balanced intake of potassium, can lead to high blood pressure (hypertension). High sodium intake does not in and of itself present a problem, but our bodies need a certain level of potassium as well for electrolyte balance. A high sodium to potassium ratio can lead to high blood pressure and even cardiovascular disease over time, especially when combined with obesity and low levels of physical activity.
Smoking cigarettes puts toxins in the blood that increase blood pressure and heart rate, constrict arteries, and thicken the blood. This combination can lead to clot formation, and a clot that forms in a narrowed artery can cause cardiac arrest or a stroke, depending on the location of the clot.
Although coffee can cause elevated blood pressure in people who don't drink it all the time, there doesn't seem to be any research showing this is a health risk. Habitual coffee drinkers appear to acclimate to the caffeine intake in a way that prevents their blood pressure from being significantly affected, provided they don't drink a whole lot more coffee than usual. Coffee hasn't been associated with health problems, but it does affect the circulatory system, which is why I mentioned it. And too much caffeine can cause rapid heartbeat and other problems.