SLEEPING A LOT VS. NOT SLEEPING ENOUGH
In the U.S., the average person gets about 7 hours and 11 minutes of sleep every day.
Although many of us struggle to get enough sleep as a result of work and life, quite a few people actually get more than enough of it.
In fact, about 8% of U.S. adults sleep at least 9 hours a day. While this may be great in some cases, sleeping more than 9 hours a day—over a long period of time—is associated with a number of issues.
- Heart disease
This isn’t to say that lots of sleep is the actual cause of these issues. That could be the case.
But another possibility is that people who sleep in a lot also do other things that lead to the problems above.
For example, perhaps those of us who sleep in all of the time don’t move around much in general. A lack of exercise can definitely lead to obesity.
On the flipside, many of us don’t get enough sleep. In the U.S., roughly 30% of the population gets less than 6 hours of sleep per day.
Like getting too much sleep, a lack of sleep is associated with people having the following:
- Heart disease
And what about blood pressure?
THE QUANTITY OF YOUR SLEEP AFFECTS YOUR BLOOD PRESSURE*
So it appears that those of us who like to sleep in, can continue to do so. At least with respect to blood pressure, sleeping a long time is unlikely to be bad for you.
For those of us who are sleep deprived, we may need to get more sleep in order to minimize our chances of getting hypertension.
QUALITY OF SLEEP
It’s important to emphasize that good quality sleep matters. In other words, insomnia may increase the chances you get high blood pressure.
According to scientists, insomnia can be seen as a combination of any of the following (on a persistent basis):
- Difficulty falling asleep
- Difficulty maintaining sleep during the night
- Waking up very early in the morning
A combination of all three increases the chances you’ll get high blood pressure later in life by about 1% to 8%.
For people who only have difficulty falling asleep:
- This may have little to no impact on your chances of developing high blood pressure.
For people who only have difficulty maintaining their sleep throughout the night:
- This may increase the chances you’ll develop hypertension by 6% to 36%
For people who wake up very early in the morning:
- This may increase the chances you’ll develop hypertension by 7% to 20%
Scientists believe that these estimates are reasonably accurate.
THE IDEAL AMOUNT OF SLEEP
In order to minimize the chances you’ll have high blood pressure, focus on getting roughly 7 to 8 hours of good quality sleep per day (all of it at night).
DOES NAPPING HELP?
Let’s say you get about 5 or 6 hours of sleep a day. Does it matter if you get all of your sleep during the night? Or should you get it in brief spurts throughout the day (by napping)?
It appears that neither is good for you.
Both, sleeping 5 to 6 hours at night or napping 5 to 6 hours throughout the day, are associated with high blood pressure.
But what about sleeping 8 or 9 hours a day? Should you get this much sleep by napping throughout the day or just sleeping at night?
- Sleeping 8 to 9 hours at night may have little to no effect on the chances you’ll get high blood pressure.
- Sleeping a total of 8 to 9 hours a day, by napping throughout the day, may increase the chances you’ll get high blood pressure.
The implication appears to be that napping, in order to catch up on sleep, isn’t going to help you.
In other words, it may be better for your body to get 8 hours of continuous rest at night than, say, 4 hours at night and another 4 hours by napping throughout the day.
It’s unclear why this is the case.
Perhaps a lack of movement (exercise) during the day, partially as a result of all of this napping, may be the actual cause behind a rise in blood pressure over time.
Regardless, there’s a lack of high quality data on the point of napping. As a result, scientists are uncertain about these estimates. Better studies are necessary.
- People under the age of 65 appear to be at greater risk of getting hypertension as a result of a lack of sleep.
- A lack of sleep may have little to no effect on the chances people aged 65 years or older develop high blood pressure.
More data is necessary to confirm these differences between the two age groups.
- It seems that women are more likely to develop high blood pressure as a result of short amounts of sleep.
- This may be truest of all for women who get 5 (or fewer) hours of sleep per day.
- A lack of sleep may have little to no effect on the chances a man develops high blood pressure.
- This might even hold true for men who sleep as little as 5 hours a day.
This general difference between genders is backed by moderate quality data. However, the exact impact of the number of hours of sleep for either gender is backed by lower quality evidence.
Men and women in the general population. Most people were 20 to 86 years old.
TYPES OF STUDIES
For adults in general: observational studies (prospective cohort). Follow-up time was at least 1 year. Hypertension was defined by the older standards of 140/90 mm Hg.
For adults based on age, gender, and napping etc: a mix of cross sectional and cohort studies.
For adults with insomnia: prospective cohort studies.
Most of the included studies on the general effects of sleep on blood pressure were of moderate to high quality.
For references, please click here.