Can High Blood Pressure Cause Insomnia?

Sleep has been known to affect the circulatory system for a long time. Obstructive sleep apnea (OSA) is a well-established risk factor for hypertension.

Research also shows that insomnia and high blood pressure are associated with each other.

Current evidence suggests that insomnia symptoms lead to an increased risk of high blood pressure, rather than high blood pressure causing sleep issues.

I’ve summarized the best research available on this topic in this short post.

Research Showing the Link Between Insomnia and High Blood Pressure

Before we look at any nuance, let’s establish that there is an association between these 2 conditions.

A meta-analysis of recent research found that (1):

Evidence indicates that the association between insomnia and elevated blood pressure or stage 1 and 2 hypertension is stronger in those with chronic insomnia, as compared to those with isolated insomnia symptoms...Insomnia is a strong candidate to join the list of risk factors for hypertension along with obstructive sleep apnea.

Diving into a few of the studies included in this report a little more reveals information about the size of this effect in those with insomnia (2, 3):

...found a 15–41% increased odds for hypertension and 52% increased odds for elevated BP compared to those without insomnia symptoms

There was also a small positive association between insomnia and increased resting heart rate.

One important thing to note about the nature of insomnia is that it rarely exists in a vacuum. People with sleep issues often have other conditions, particularly anxiety and depression, which is why more research needs to be done in order to understand the link between sleep issues in particular and cardiovascular health.

SummaryThere is ample evidence that people with insomnia are much more likely to have elevated blood pressure and develop hypertension.

Short Sleep Duration May Be the Key Factor

Insomnia can come in many forms.

One of those forms that has been studied in this area is insomnia with short sleep duration (usually defined as less than 6 hours of sleep in studies).

For example, one study found (4):

Participants who reported poor sleep or chronic insomnia and slept objectively more than 6 hours were not associated with increased odds...

In other words, some people with insomnia are not at a higher risk for elevated blood pressure as long as their total sleep time is long enough.

Two other studies found a similar correlation between short total sleep duration and hypertension risk (5,6).

They found that patients with insomnia AND short sleep duration were 3 times more likely to report hypertension as a problem than patients with insomnia and normal sleep duration.

An important note that this relationship was only significant in objectively measured sleep duration data. In other words, people are terrible at accurately perceiving and reporting how long they sleep.

SummaryCurrent evidence points towards short sleep duration (which is just a single criteria of insomnia) being the most important link to an elevated risk of high blood pressure.

High Blood Pressure Risk is Higher in Insomniacs With Depressive Symptoms

Insomnia, anxiety, and depression are all highly related to each other. It’s common for people with one of those conditions to develop one or both of the other.

There isn’t much research on high blood pressure and insomnia with either anxiety or depression present, but there is some.

One study of major depression patients with self-reported insomnia found (7):

In major depression, severe objective insomnia and lower self-reported insomnia complaints are associated with higher risk of high blood pressure

More specifically, they found that high blood pressure was present in 32% of subjects with major depression.

These patients were also more likely to heavily drink, be overweight, and have severe insomnia symptoms (as opposed to less severe or moderate). There are obviously a lot of confounding factors, which is why this is a tough topic to study.

SummaryThose with severe insomnia will likely have short sleep duration, but they may also have depressive symptoms that could elevate the risk of hypertension further. More research is needed in this area.

Does High Blood Pressure Cause Insomnia or the Other Way Around?

Most of this research is correlational, because it’s not easy to do a study where you do something like induce high blood pressure in patients for an extended period of time.

However, the research so far seems to indicate that insomnia leads to high blood pressure, rather than high blood pressure causing sleep issues.

One way we can see that more clearly is to look at a few smaller studies that looked at the effects of sleep deprivation on blood pressure. These reliably found that even a night of sleep deprivation has immediate effects on blood pressure (8,9):

The diastolic blood pressure was significantly higher after total sleep deprivation than after control sleep

Sleep deprivation is a stressful event, so it’s not that surprising of a result.

SummaryEverything we’ve looked at shows that insomnia puts people at an increased risk of developing high blood pressure. In particular, it seems that severe insomnia (with short sleep duration), and those with other coexisting symptoms like depression are at an even greater risk.

References

1. Insomnia, Short Sleep Duration, and High Blood Pressure
2. Associations of Sleep Duration and Disturbances With Hypertension in Metropolitan Cities of Delhi, Chennai, and Karachi in South Asia
3. Associations of Insomnia Symptoms With Blood Pressure and Resting Heart Rate
4. Insomnia with objective short sleep duration is associated with cognitive impairment
5. DSM-5 Insomnia and Short Sleep: Comorbidity Landscape and Racial Disparities
6. Objective but Not Subjective Short Sleep Duration Associated with Increased Risk for Hypertension in Individuals with Insomnia
7. Risk of high blood pressure associated with objective insomnia and self-reported insomnia complaints in major depression
8. Effects of insufficient sleep on blood pressure in hypertensive patients
9. Total Sleep Deprivation Elevates Blood Pressure Through Arterial Baroreflex Resetting