Cramp or Charley Horse
A muscle cramp is a sudden and involuntary shortening of your muscles, which becomes tight, known as a spasm. They can be very painful and make it hard to move, with an average cramp lasting from a few seconds to 10-minutes.
Chances are you’ve already experienced one. Cramps can be ongoing and disruptive, occurring at inopportune times like in the middle of the night while you are sleeping, or walking across the road.