This sharp sensation at the tip of your fingers is usually a combination of a minor bone bruise, damaged nerves and damaged muscle tissue from using too much pressure when fretting a guitar and extended use.
Your hand is full of what are called peripheral nerves that go from your spinal cord to your arms, hands, legs and feet. The nerve endings of the fingers are heavily concentrated on the palmar aspect (the finger surface on the palm side of the hand). There are 2,500 receptors per centimeter squared just on the fingertips!
Pain is sensed by free nerve endings, mostly located in the skin, bones, and joint capsules, and around blood vessels.
While resilient, the hand the one of the most commonly damaged part of the human body. A rigorous guitar playing session involves repeated stress to the hands and finger tips causing muscle, bone and nerve damage.
This tingling, sharp sensation guitar players experience is from overuse and can be avoided with proper stretching and warming up/cooling down. Additionally, heat or cold can help soothe the pain along with proper rest!