Since this is the "penis" discussion group, I am going to take it that we are talking about your penis. I haven't seen too many guys whose head of the penis hurt unless the somehow injured it. But if you are feeling some sort of painful sensitivity on the head of your penis and it is persisting, I would strongly suggest you see your doctor or health care professional. You never know and its best to have a pro tell you 'yea or nay' as to whether there is a problem or not.
The head of your penis is called the glans. The glans and the inside of your foreskin are mucous membranes, the same type of tissue that is inside your mouth and under your eyelids. It feels sticky because it is. Touch inside your mouth - it is damp and wet. Because it is mucous membrane, your glans should not be washed with harsh soap. Usually it is best to rinse it with water, and possible use a body wash or a very mild soap.
Also, the glans is very sensitive for uncircumcised guys because it is always protected by the foreskin. Teenage guys when they first start experimenting with their penis may find that the glans is waay tooo sensitive. Exposing the glans to the air or to a stream of water when bathing/showering will, in time, overcome that too sensitive feeling.