Meditation is a mind and body practice. There are many types of meditation practices, most of which originated in ancient religious and spiritual traditions. Some forms of meditation instruct the practitioner to become mindful of thoughts, feelings, and sensations and to observe them in a nonjudgmental way.
How much do we know about meditation practices?
Many studies have been conducted to look at how meditation may be helpful for a variety of conditions, such as high blood pressure, certain psychological disorders, and pain. A number of studies also have helped researchers learn how meditation might work and how it affects the brain.
What do we know about the effectiveness of meditation?
Some research suggests that practicing meditation may reduce blood pressure, symptoms of irritable bowel syndrome, anxiety and depression, and insomnia. Evidence about its effectiveness for pain and as a smoking-cessation treatment is uncertain.
What do we know about the safety of meditation?
Meditation is generally considered to be safe for healthy people. However, people with physical limitations may not be able to participate in certain meditative practices involving movement.
Source: https://nccih.nih.gov/health/meditation/overview.htm