Search tips
Search criteria 


Logo of bmjThis ArticleThe BMJ
BMJ. 2007 October 13; 335(7623): 745.
PMCID: PMC2018818
Shortcuts from Other Journals

Measure blood pressure both day and night

Blood pressure helps predict risk of cardiovascular disease and death, and since the early 1990s doctors have been told that blood pressure measured during the night is a better predictor than blood pressure measured during the day. This may not be true, say researchers.

Pooled data from six cohorts in Europe, Asia, and South America suggest that daytime blood pressure is just as good as night time blood pressure for predicting fatal and non-fatal cardiovascular events. Night time blood pressure and the ratio of night time to daytime blood pressure are good for predicting deaths only. So if you want the full picture, it is important to take measurements for at least 24 hours, say the authors. The blood pressure ratio may not be as useful as many doctors think.

This analysis included more than 7000 adults followed up for nearly 10 years. There were 387 deaths from cardiovascular disease, 420 strokes, and 390 coronary events. So the researchers' estimates are probably the most accurate so far.

Daytime blood pressure wasn't a particularly good prognostic indicator in people taking antihypertensive drugs. Perhaps 24 hour measurements should be interpreted differently in this subgroup, says a linked comment (p 1192).


  • Lancet 2007;370:1219-29

Articles from The BMJ are provided here courtesy of BMJ Publishing Group