But, there is a special system at work in our bodies that makes the movement possible. And when it doesn't work, the results can be devastating.
It can happen to anyone at anytime. But for some reason, teenage girls seem more susceptible to one form of the disorder.
Thirteen-year-old Jenna Ragen looks and acts like most teenage girls, that is until her body starts to play tricks.
"You get real dizzy and kinda have to take a minute and you are like woah," said Ragen.
Madie Nixon, also 13, knows the feeling. Playing softball was her passion until she started having strange symptoms like Jenna's.
"I'm always dIzzy. There's never a time where I'm not," said Nixon.
Jenna and Madie have both been diagnosed with an illness you've probably never heard of. It's called postural orthostatic tachychardia syndrome or POTS.
One study claims it may be hitting one in five teens. For many patients, it literally zaps away their energy.
"As we watched her, she changed into a different child," said Suzannah Ragen, Jenna's mother.
"She just doesn't function as well as she used to. Everything is harder for her. Everything," said Hope Chalmers, Madie's mother.
Months of frustrating trips to specialists with no answers eventually led these families to Dr. Barbara Deal at Children's Memorial Hospital. She runs a POTS clinic.
"It really exists, it's a big problem and it's a bit difficult to diagnose," said Dr. Deal, pediatric cardiologist.
POTS has to do with a disturbance in the body's autonomic nervous system which works like a thermostat. For some reason, it can't adjust to the pull of gravity when standing up. That can affect circulation. Blood vessels don't constrict as well and not enough blood moves through out the body.
Signature symptoms can include dizziness, passing out, especially when going from a sitting to a standing position. Other problems include excessive fatigue, weakness, headaches, even forgetfulness.
But what teenager doesn't complain of being tired? Experts say POTS is different because the symptoms dramatically alter a patient's life. .
"You're going to get better but not as fast as you want," said Dr. Deal.
Dr. Deal says it's not easy to diagnose POTS because the symptoms can seem fairly common.
The childhood form is likely to strike around the age of 14 affecting more girls than boys.
The cause? No one's sure but experts say it tends to follow a growth spurt or may be linked to puberty. Many report it starting after a viral infection such as a flu or a cold.
"They think that maybe it trips something in the hypothalamus somewhere in the brain that regulates blood pressure control," said Dr. Blair Grubb, electrophysiologist.
Dr. Grubb at the University of Toledo Medical Center is one of the premiere experts researching the mysterious disorder.
"Some children have a very mild form where it is only a minor inconvenience and for other children it is so severe they are bedridden and devastated," said Dr. Grubb.
It may sound ironic but doctors will often recommend exercise which may help strengthen weakened arteries. Also, keeping the body well hydrated may help improve circulation as can maintaining a higher sodium intake.
Medications can be prescribed in some cases but most patients just have to wait it out.
Jenna Ragen says the hardest part was finding a diagnosis and then convincing people POTS is real.
"Some people don't understand because I don't look like I have this disease," said Ragen.
Adults can also get POTS.
The good news for many people it eventually goes away. But it can take years.
How do you know if your child has POTS? They would have to undergo testing that would include ruling out other illnesses. A simple case of dizziness or lethargy doesn't necessarily mean a teen has the disorder.
For more information:
Dr. Barbara Deal
Children's Memorial Hospital
2300 Children's Plaza
Chicago, Illinois 60614
Blair P. Grubb MD
Professor of Medicine and Pediatrics
Director: Cardiac Electrophysiology Service
Health Science Campus
University of Toledo School of Medicine
3000 Arlington Ave
Toledo, Ohio 43560
The University of Toledo, Medical College: www.utoledo.edu
Dysautonomia Information Network: www.dinet.org
Dysautonomia Youth Network of America: www.dynakids.org
National Dysautonomia Research Foundation: www.NDRF.org
Syncope Trust UK: www.stars.org.uk