At five-feet tall, 13-year-old Daniel Clark of Harlem in New York City is considered one of the easier boys to pick on simply because he is shorter than the rest of his classmates.
"He had been attacked, mugged, five times outside the school," said Daniel's father, Daniel Clark Sr. "Every time he leaves the house you have to, 'oh my God, hope nothing happens to him.'"
Daniel has always been around the bottom tenth percentile for height. At his previous school, Daniel said was cut from sports teams, picked on, and had to work harder to prove his talents because of his height.
"I may be short in appearance, but not in personality," Daniel said.
Unlike his son, Daniel Clark Sr. was already 6 feet tall when he was his son's age. And although his mother is five feet tall, doctors said they are uncertain how tall Daniel will grow. His father says it's hard to watch his son feel so set back because of his height.
"He's a nice guy, who in terms of stature happens to be small in size," said Clark. "We've both been thinking perhaps he might get a growth spurt."
Concern about the slow growth of a child is common among parents and anxiety is often greater when the child is a boy, according to a study published in the British Medical Journal.
For boys, growth spurts occur around age 13, but may begin as early as age 10 or as late as age 16. And on average, girls will have their greatest growth two years earlier than boys, said ABC News Senior Health and Medical Editor, Dr. Richard Besser.
However, according to Dr. Joseph Zanga, chief of pediatrics at Columbus Regional Health Care System in Columbus, Ga., each child has a different growth potential.
"Even a child at the 50th percentile may be normal, "he said, "but if they're whole growth life they were at 90th percentile of growth and then drop to the 50th percentile, normal is not necessarily normal then."
Children are generally considered of short stature when they are shorter than 98.8 percent of other children of the same gender and age, according to the Food and Drug Administration. While factors like eating right and plenty of physical activity help ensure a child grows normally, genetics also plays a major part in determining how tall a child will grow, said Zanga.
"If everybody in my family never gets taller than 5 feet, then I will be content that my son has reached his potential," said Zanga. "If all of my family is 6 foot tall and my child doesn't look like he's going to make it at all, I might be concerned."
According to Besser, parents should talk to a pediatrician if their child is growing less than two inches a year, if a child is not gaining or losing any weight, or if a child is frequently coughing or experiences infections.
Severe obstacles to growth for some children include malnutrition, thyroid deficiency, or heart and lung diseases. Pediatricians use history and physical evaluations that may include taking a closer look at the aging of the bones through x-rays to understand what is hindering some children to grow.
One in 3,800 children born suffers from growth hormone deficiency, according to the Child Growth Foundation, and some may require hormone injections to reach their potential height. Children with short stature make up one- third of all children receiving growth hormone therapy in the U.S., according to a 1999 article published in the New England Journal of Medicine. Twice as many boys as girls are treated with growth hormone for short stature, according to a recent study published in the Journal of Clinical Endocrinology and Metabolism.
"The injections only get them around the height they would be had they not had a lack of the hormone," said Zanga.
According to Dr. Richard Levy, pediatric endocrinologist at Rush Presbyterian Hospital in Chicago, children will grow an average of 2.5 inches when on hormone therapy for about 10 years. However, the length of time a child is placed on hormone therapy depends on bone- age evaluation, or an x-ray of hands and wrists to see how much more he or she is able to grow, he said.
While growth hormone injection is generally safe, using the hormone may unmask a thyroid deficiency in some children once they stop therapy, he said.
"About 20 percent who were not before on thyroid medication end up on thyroid medication after they stop growth hormone," said Levy.
But not all children who feel shorter than their peers would benefit from growth hormones. For boys like Daniel, who may feel disadvantaged because of their short stature, Zanga said family encouragement may be a better treatment option.
"Sometimes the way to treat it is to redirect the family's way of thinking so the child will understand that he can do other things that will make them feel successful," said Zanga.
Parents should help their child understand that height should not be a defining factor in success, according to Besser.
"See what are their strengths and what is it that they excel at," said Besser. "What is it that they get excited about and helping them define themselves through their quality their characteristics."
Contrary to popular belief, many studies suggest that height is not related to success in life and does not have a lasting impact on self-esteem.
"If you're a jockey you'd rather be short stature, and if you're a basketball player you'd rather be tall," he said. "So depending on what you see as success, you may find yourself on the losing end."
While anecdotal evidence may suggest that size matters, others more likely rely on talent and ability to get the job done, said Zanga.
According to Zanga, in the business world, many people may see those who look taller as those who have a higher confidence level. But conflicting research shows that's hard to prove.
Although some call him short, but that's not the words Daniel uses to describe himself.
"Determined, opposite of shy, charismatic, hardworking," he said.
Daniel said it took a lot for him to rebuild his confidence after being bullied.
"It's something you have to work through if you're a short person," he said. "It tore me down a few times."
Today Daniel attends Democracy Prep Charter School in Harlem where he said he has outgrown feeling held back by this height.
"You only have one life and one person to live with, which is yourself," he said. "It's something you got to learn how to do."