We may yawn when we are sleepy, tired, or bored. Our mouth opens wide, and we take a deep breath. Yawning is a very normal body reaction.
Scientists do not know the full reason for yawning. It may help the brain become more awake. It may also be a sign that the body wants to rest.
Yawning can also seem to spread from one person to another. When one person yawns, another person may want to yawn too. This may happen because we react to people around us.
Normal yawning is not dangerous, but very frequent yawning may be a health signal.