Relaxation and its effect on blood pressure and nerves

Blood pressure refers to the force your blood places on the walls of your arteries as your heart pumps it through your body. It is recorded using two numbers:

Systolic pressure: the highest pressure in the arteries when the heart contracts.

Diastolic pressure: the lowest pressure when the heart is at rest between beats.

The unit for measuring blood pressure is mmHg (millimeters of mercury). In healthy adults, the ideal blood pressure is usually around 120/80 mmHg. If blood pressure is high or low for a long time, it can cause serious problems for the heart, brain, kidneys, and other organs.

The role of the autonomic nervous system in blood pressure

The autonomic nervous system (ANS) is a part of the peripheral nervous system, responsible for controlling the body’s unconscious activities, that is, functions that occur automatically and that we do not need (and often cannot) control by will.

Human blood pressure is not fixed and changes continuously with physical activity, emotional state, and internal demands. One of the important “controllers” that helps maintain this stability is the autonomic nervous system (ANS).

The mechanism of action takes place through the coordination of two branches:

• Sympathetic nervous system (SNS): When the body needs more energy (for example, when stressed, exercising vigorously, or in danger), the SNS will make the heart beat faster and stronger, and at the same time constrict blood vessels in many areas, causing blood pressure to increase rapidly. This process makes sure key organs and muscles get the oxygen and blood they need.
• Parasympathetic nervous system (PNS): When the body is at rest, the PNS slows the heart rate and dilates blood vessels, helping to reduce blood pressure to normal levels.

In addition, the ANS also interacts with other mechanisms such as the baroreceptor reflex, sensors located in the carotid and aortic artery walls, which detect changes in blood pressure and send signals to the brain to immediately adjust cardiovascular activity.

In other words, the ANS acts as an “auto-regulator”, constantly balancing between increasing and decreasing blood pressure to ensure effective blood circulation without putting too much pressure on the heart and blood vessels.

When stress persists, the body often gets stuck in a state of overactive SNS. At this time, hormones such as adrenaline and cortisol are continuously released, causing blood vessels to constrict, the heart to beat faster, and chronically high blood pressure. This is one of the common causes of high blood pressure and cardiovascular complications.

How relaxation techniques restore balance and lower blood pressure

Relaxation techniques aim to reduce SNS activity and increase PNS activity, helping the body return to a state of balance. Some effective methods include:

1. Deep breathing

One of the simple but effective methods is deep breathing. When applying the diaphragmatic breathing technique or “belly breathing”, the flow of air deep into the lungs stimulates the vagus nerve, slowing the heart rate and lowering blood pressure. Breathing slowly for 4–6 seconds, holding the breath for 1–2 seconds, and then exhaling for 6–8 seconds can bring about remarkable effects.

2. Meditation

Meditation is also a powerful tool, helping to calm overactive nerve impulses and lower stress hormone levels. By sitting still, focusing on breathing or a mantra for 10–20 minutes a day, the PNS will be activated, leading to a decrease in both systolic and diastolic blood pressure.

3. Yoga

In addition, yoga combines gentle movements, regulated breathing and mental focus, helping to improve heart rate variability. Gentle yoga exercises such as Hatha or Yin before bed can help regulate blood pressure.

4. Progressive muscle relaxation

Another method is progressive muscle relaxation, in which the practitioner tenses and relaxes muscle groups in turn. Each muscle group is tensed for about 5 seconds and then relaxed for 15–20 seconds. This technique sends a “safe” signal to the nervous system, stimulating PNS activity and reducing stress on the heart.

5. Biofeedback

Modern technology supports this process through biofeedback. By monitoring heart rate or muscle tension in real time, the practitioner learns to regulate physiological responses to achieve optimal relaxation.

6. Mindfulness

Finally, mindfulness helps the mind escape the cycle of anxiety by focusing fully on the present. Just pay attention to the feeling of breathing, body or surrounding sounds for a few minutes, the SNS will calm down, the PNS will be more active and blood pressure will decrease naturally and sustainably.