Breathing hyperbaric air causes a syndrome of behavioral and subjective effects called nitrogen narcosis, which limits the work efficiency of divers and is ultimately life-threatening.

There is no specified age limit to sport diving. However, most elderly divers are not capable of sustaining the work load required by all but the least physically demanding dives.

Sea sickness or Motion Sickness, is a condition in which a disagreement exists between visually perceived movement and the vestibular system's sense of movement.

There are no known studies on the use of marijuana and diving but by general analogy a number of effects are harmful to divers.