Some people just can't make it without that morning cup of coffee. Still others are constantly on the lookout for their next chocolate fix.
But for millions of people across the country, "gotta have it" refers to e-mail, Internet, and text messaging -- in the palms of their hands.
Use of these wireless communications devices has picked up in recent years and continues to rise as more gadgets hit the market. Canadian-based company Research in Motion (RIM) announced June 28 that it would ship its 20 millionth BlackBerry hand-held device this summer, followed today by the much anticipated release of Apple's multimedia jack-of-all-trades, the iPhone.
It seems as though this trend toward go-anywhere electronic communication is not about to die out anytime soon.
But as with all inventions that have the potential to become vices, moderation is key, lest users find themselves unable to turn a key or twist a doorknob because their thumbs are too sore from typing and pressing buttons.
"They are really repetitive stress injuries -- pain, numbness, discomfort in the base of the thumbs from overuse," said Margot Miller, a physical therapist and president of the Occupational Health Section of the Orthopedic Section of the American Physical Therapy Association.
These sorts of injuries, known as repetitive strain injuries or a repetitive motion disorders, can lead to serious medical problems.
"I've seen a significant increase in the number of people with pain in their tendon regions in their thumbs and their fingers," Dr. Richard Brown, an orthopedic hand surgeon at the Scripps Memorial Hospital in La Jolla, Calif., said.
"I have to send them to the therapist or start them on medicine or put them in splints or, sometimes even operate."
According to Dr. Andre Panagos, a sports medicine specialist and assistant professor at Weill Medical College of Cornell University, "They can get so bad that you have chronic pain forever and that you need surgery, which may or may not really relieve it."
These injuries often result from people overusing their hands in unnatural ways. By conducting the same movement over and over again, like moving their thumbs back and forth to type messages on a Treo, Sidekick, BlackJack, or other device, users can wear out the joints and tendons in their hands.
"Our thumbs are what we used to grasp things -- like keys or bottles or glasses, and that's what they are primarily made for," said Panagos. "We're basically overloading the joint, trying to give it much more dexterity which it naturally doesn't have, and the tendons around it get inflamed."
"You get a generalized pain that you can't quite describe but you can really feel because every time you do that motion, it starts to hurt," Panagos said.
Brown adds that overusing the thumb can sometimes lead to a painful pinch the area around the joint.
"The tendon will get constricted in that area and pain or inflammation will result," he said.
The best way to avoid pain from using these devices, experts say, is to be cautious. Panagos suggests paying more attention to your body to understand what its limits are.