Childbirth is a perfect example of the meaning of this word for pressure. Childbirth is a process of pressure that forces a baby out into the world. The pain associated with the pressure of childbirth is part of God's judgement for Adam and Eve's disobedience. It is straight, as if walking down a haaway, between two walls. And it is narrow, a way of pressure.
Pressure provides resistance in our lives.
Resistance makes us struggle. Struggling makes us strong. It is the road that leads to life. Walking the wide road does nothing for us, it's an easy journey, there is no resistance, and therefore growth is haphazard and weak. Anybody who works with timber will tell you that the strongest lumber comes from trees that have been tested and proven by storms.