Heart Disease
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Poor sleep has been linked to all kinds of heart problems, including high blood pressure, atherosclerosis, heart attack, and stroke. Just a single bad night can cause a person with hypertension to have elevated blood pressure throughout the next day. Knutson says part of the problem seems to be that lack of sleep not only reduces activity of the parasympathetic nervous system but increases that of the sympathetic nervous system – the one we associate with fight or flight.