What causes blood pressure to go up at night

In most cases, it's not clear exactly what causes high blood pressure. But there are things that can increase your risk.

Table of Contents Show

Things that can increase your risk of getting high blood pressure
Known causes of high blood pressure
Getting enough sleep helps keep your mind and body healthy, and could be important for your blood pressure too.
Does your blood pressure change while you sleep?
How can lack of sleep affect your health?
What is Obstructive Sleep Apnoea (OSA)?
How can you get enough sleep?
Is it normal for blood pressure to rise at night?
What should I do if my blood pressure is high at night?

Things that can increase your risk of getting high blood pressure

You might be more at risk if you:

are overweight
eat too much salt and do not eat enough fruit and vegetables
do not do enough exercise
drink too much alcohol or coffee (or other caffeine-based drinks)
smoke
do not get much sleep or have disturbed sleep
are over 65
have a relative with high blood pressure
are of black African or black Caribbean descent
live in a deprived area

Making healthy lifestyle changes can sometimes help reduce your chances of getting high blood pressure and help lower your blood pressure if it's already high.

Find out more about how to prevent high blood pressure

Known causes of high blood pressure

In about 1 in 20 cases, high blood pressure happens as the result of an underlying health condition or taking a certain medicine.

Health conditions that can cause high blood pressure include:

kidney disease
diabetes
long-term kidney infections
obstructive sleep apnoea – where the walls of the throat relax and narrow during sleep, interrupting normal breathing
glomerulonephritis – damage to the tiny filters inside the kidneys
narrowing of the arteries supplying the kidneys
hormone problems – such as an underactive thyroid, an overactive thyroid, Cushing's syndrome, acromegaly, increased levels of the hormone aldosterone (hyperaldosteronism), and phaeochromocytoma
lupus – a condition in which the immune system attacks parts of the body, such as the skin, joints and organs
scleroderma – a condition that causes thickened skin, and sometimes problems with organs and blood vessels

Medicines that can increase your blood pressure include:

the contraceptive pill
steroids
non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen and naproxen
some pharmacy cough and cold remedies
some herbal remedies – particularly those containing liquorice
some recreational drugs – such as cocaine and amphetamines
some selective serotonin-noradrenaline reuptake inhibitor (SSNRI) antidepressants – such as venlafaxine

In these cases, your blood pressure may return to normal once you stop taking the medicine or drug.

Page last reviewed: 23 October 2019
Next review due: 23 October 2022

Getting enough sleep helps keep your mind and body healthy, and could be important for your blood pressure too.

Does your blood pressure change while you sleep?

When you’re asleep your blood pressure is generally lower than while you’re awake. This is totally normal and is known as nocturnal dipping. The drop in both your systolic (the top number) and diastolic (bottom number) blood pressure can be up to 20% lower than your readings in the day time.

People who don’t have lower blood pressure while they sleep have been shown to be at higher risk of heart disease and stroke.

How can lack of sleep affect your health?

A night of bad sleep can affect your mood and concentration the next day, but it won’t affect your overall health. But a regular lack of sleep can have a bigger effect. In the long run, you’re more likely to become overweight or obese and develop problems including high blood pressure, diabetes and heart disease.

How can lack of sleep affect your blood pressure?
Many studies have shown people who have trouble sleeping are more likely to have high blood pressure. Sleeping less than five hours a night, insomnia and interrupted sleep all appear to raise blood pressure. This effect seems to be stronger in women than in men, and during middle-age.

How can shift work affect your blood pressure?
Shift work can be very disruptive to your sleep patterns and how much sleep you get. There is research linking shift work to health problems including being overweight, high cholesterol and diabetes, and it could raise your blood pressure too.

What is Obstructive Sleep Apnoea (OSA)?

Obstructive Sleep Apnoea (OSA) is a condition which interrupts sleep because it causes difficulty breathing.

With OSA, the walls of the throat relax during sleep, blocking your airways so you can’t breathe for a short period of time. The lack of oxygen wakes you up or brings you into a lighter sleep so that your airways can open up and your breathing can return to normal. These episodes can happen throughout the night, affecting your sleep.

People with OSA are more likely to develop high blood pressure – it’s estimated that half of people with OSA have high blood pressure. It also means you’re more likely to develop type 2 diabetes, atrial fibrillation, a stroke or a heart attack.

What causes OSA?
OSA is most common in people who are very overweight as this can put a strain on the throat muscles. It’s more common in men than women and tends to affect people over 40. Your lifestyle, any medicines you’re taking and your genes can all play a role too.

Losing weight if you need to, stopping smoking and drinking less alcohol can all help to lower your risk of developing OSA.

Treating OSA
The signs and symptoms of OSA can include snoring and laboured breathing, as well as interrupted breathing and gasping for breath. You might not know you have it – it’s often noticed by a partner. Visit your GP if you think you might have OSA as it can be treated.

Find out more from NHS Choices.

How can you get enough sleep?

Most people need about eight hours of sleep a night, but everybody’s different. Lack of sleep can be caused by problems such as sleep apnoea, but it’s usually due to unhelpful sleeping habits and routines.

There is lots of advice available to help you get enough sleep, for example, figuring out how much sleep you need and working out a regular routine and sticking to it. Winding down before bed can help, for example with a warm bath or writing down anything that’s on your mind so you can deal with it the next day.

The NHS has more information and ideas for getting a good night’s sleep. Read more about meditation to improve sleep from BeMindful.co.uk.

Is it normal for blood pressure to rise at night?

A rise in blood pressure overnight to early morning has been linked to an increased risk of heart disease. An irregular blood pressure pattern could also mean that you have: Poorly controlled high blood pressure. Obstructive sleep apnea.

What should I do if my blood pressure is high at night?

“The most important way to lower your risk of an acute nocturnal spike in your blood pressure is to maintain a consistent sleeping pattern,” added Pianko. “Try to go to sleep and get up at the same time each day. Avoid alcohol and caffeine before bed. Exercise earlier in the day.