There are sprint hurdle races and long hurdle races. The standard sprint hurdle race is 110 meters for men and 100 meters for women. The standard long hurdle race is 400 meters for both men and women.
Each of these races is usually run over ten hurdles. The International Association of Athletics Federations is the worldwide governing body for track and field events including hurdles. Associations at the national, state and local level generally follow IAAF rules, though there may be some marginal variations.

In the 110 meter event, the hurdles are1.067 meters high. The first hurdle is set 13.72 meters from the starting line. There are 9.14 meters between two hurdles and 14.02 meters from the final hurdle to the finish line.
In the 100 meter event, the hurdles measure .84 meters in height. The first hurdle is set 13 meters from the starting line. There are 8.5 meters between hurdles and 10.5 meters from the final hurdle to the finish line.
In the 400 men race the hurdles are .914 meters tall. The first hurdle is set 45 meters from the starting line. There are 35 meters between hurdles and 40 meters from the final hurdle to the finish line.  The hurdle placement in the 400 meter women’s race is the same as the men’s 400 meters except that the hurdles are .762 meters high.
There are however some variations on hurdle height and spacing of hurdles depending on the age groups of the contestants.
Hurdle races usually have eight contestants in the final. Each hurdle event may entail two or three preliminary rounds before the final – depending on the number of entrants. Runners in all hurdle events begin in starting blocks and wait to hear announcements, “On your marks,” and then, “Set.” When the “Set” call is announced, the contestants must have both their hands and at least one knee touching the ground and both feet in the starting blocks. The participants are allowed only one false start and are disqualified if there be a second.

As in all other athletic races, the hurdle race ends when a runner’s torso crosses the winning line. Interestingly, contestants are not disqualified for accidentally knocking a hurdle over - though it may be viewed seriously if the hurdle is knocked down willfully. Again, racers can be disqualified for omitting to jump a hurdle or trailing a foot or leg below the horizontal plane of the top of any hurdle while clearing it.

Hurdlers who wish to successfully compete in hurdle races will require the speed of a sprinter as well as the technical skills to clear the hurdles. Runners typically take seven to eight strides before hurdle one, then use a three-stride pattern for the rest.

Hurdles are also one of the Athletic Equipments and in all levels of hurdle race competitions, hurdlers are required to clear each of the hurdles. A hurdler who circumvents a hurdle or avoids jumping a hurdle is automatically disqualified. Runners who trail a leg or foot below the horizontal plane of the hurdle's top at the moment of clearance also are similarly disqualified. The rules also require hurdlers to stay in their own lane throughout the race.