When we think of sleep, we often think of it as the body is at its most relaxed state. However, for some people, nighttime is not the time when the cardiovascular system rests. Instead, blood pressure can silently increase without being detected.
Normally, blood pressure is measured during the day, when the body is awake and active. But according to experts, blood pressure at night (ie blood pressure when you are sleeping) can be a more accurate predictor of cardiovascular disease than daytime readings.
Some studies show that people with high blood pressure while sleeping are at significantly higher risk of conditions such as heart failure, stroke, and coronary artery disease, even if their daytime blood pressure is completely normal.
Mechanism of nocturnal hypertension
Blood pressure tends to increase slightly at night in some people as the body tries to excrete sodium (salt) through the kidneys. This is common in people who are sensitive to salt or have an excessive salt intake. If blood pressure is not high enough during the day to excrete salt, the body will “force” blood pressure to increase at night as a compensatory mechanism, and this inadvertently harms the cardiovascular system.
In addition, a number of other factors can also increase blood pressure at night such as:
- Sleep apnea
- Autonomic nervous system disorders
- Chronic stress
- Poor quality sleep
- Underlying diseases such as diabetes, kidney disease, hyperthyroidism, prostate enlargement.
How to detect and control blood pressure at night?
1. How to detect high blood pressure at night
High blood pressure at night often has no obvious symptoms, because it occurs while you are sleeping. However, some unusual signs may reflect an increase in nighttime blood pressure:
- Waking up in the middle of the night with a feeling of rapid heartbeat, anxiety, shortness of breath
- Headache when waking up in the morning
- Prolonged insomnia of unknown cause
- Sleep apnea (may be due to loud snoring, gasping when waking up)
If you have these symptoms, especially if you have a history of high blood pressure, consider the possibility of increased blood pressure during sleep.
2. How to effectively control nighttime blood pressure
Controlling nighttime blood pressure is not simply a matter of drug treatment, but is also closely related to living habits, sleep quality and the time of taking medication.
2.1. Optimizing the timing of medication
Many studies have shown that taking antihypertensive medication in the evening (instead of the morning) can help:
- Maintain the effect of the medication throughout the night
- Reduce the rate of nocturnal cardiovascular events (stroke, myocardial infarction)
- Support the regulation of blood pressure circadian rhythms (tends to decrease slightly at night and gradually increase in the morning)
However, changing the timing of medication requires a doctor’s prescription and should not be adjusted on your own.
2.2. Improve sleep quality
Deep and regular sleep is an important factor in helping blood pressure stabilize throughout the night. Please note:
- Go to bed and wake up at the same time, even on weekends
- Avoid using electronic devices before bed (blue light disrupts melatonin)
- Do not drink caffeine or alcohol after 5pm
- Limit salty foods for dinner
- Do not exercise vigorously after 8pm
- Light meditation, listening to relaxing music, or reading paper books are good habits to help the body fall into deep sleep.
2.3. Treat related diseases
Some underlying diseases can increase the risk of high blood pressure at night, for example:
- Sleep apnea: needs to be diagnosed with a sleep monitor and treated with a CPAP device if necessary.
- Diabetes, kidney disease, thyroid disorders: need to be controlled to avoid affecting blood pressure.
- Autonomic nervous system disorders: in the elderly, or people with long-term cardiovascular disease.
2.4. Long-term lifestyle adjustments
Maintaining healthy habits will help prevent and control nocturnal hypertension:
- Reduce salt in your diet (less than 2g sodium/day)
- Eat foods rich in potassium (bananas, avocados, green vegetables)
- Increase physical activity during the day
- Maintain a healthy weight
- Avoid emotional stress in the evening
