Pain, is an unpleasant physical or emotional feeling. It is subjective with no satisfactory objective ways of measuring it. This makes it hard to prove which hurts the most, childbirth or getting kick in the balls. The perception of pain may differ from person to person, depending on mood, alertness, and capacity to endure the pain.
Nociceptors are nerve cells that send pain signals to the spinal cord and brain. The frequency of firing of these sensory neurons determine the intensity of pain. Typically, the pain of getting kicked in the balls may only last 5-10 minutes but the testicles are wrapped with nociceptors making it really painful.
A woman's labour may last for more than 12 hours, in which there are regular contraction of her womb's muscles. There is also an increased pressure on the cervix, stretching of the birth canal and vagina. The perception of the severity of labour pain differs from pregnancy to pregnancy.
Due to the very subjective perception of pain, there may not be an agreed conclusion as to what hurts more between childbirth and a kick in a man's testicles.