Crying is a physically depleting process which is why adults feel exhausted after a good cry, according to experts.
Lauren Bylsma, professor of psychology at the University of Pittsburgh, explained that the level of fatigue a person experiences also depends on how strenuously they have cried.
She added that when a person cries then the whole body is affected and it is physically exhausting.
Added to that, the person experiences an increase in their heart rate and their breathing slows down, leading to hyperventilation.
More strenuous crying leads to higher hyperventilation, thus the oxygen supply to the brain also gets reduced causing drowsiness.
However, crying has a lot of benefits in terms of mental health. It can reduce stress by releasing endorphins, a natural painkiller, and oxytocin, which helps in calmness.