Texting, the thing we do most with our phones, takes a toll on our health.

Some doctors point to how smartphone users have reported soreness or numbness in their hands and wrists after texting for an extended period of time."I think we may see more problems in terms of hand disorders, such as tendinitis, repetitive strain injuries, arthritis, thumb arthritis down the road, and even possibly carpal tunnel syndrome," said Dr. Sanjeev Kakar, an orthopedic surgeon at the Mayo Clinic in Rochester, Minnesota."Kids 20 years ago were not using handheld devices, and now they're using them all the time in schools and at home. We may be at the tip of an iceberg, and we're going to see a cumulative effect," he said."I don't think this will happen if you've texted once in your life. I think the process of doing this over 20 to 30 years may lead to having these problems down the road."On the other hand, some doctors have noted that there are no official medical diagnoses for technology-related hand and wrist problems, and just because such problems correlate with smartphone use does not mean they are caused by smartphone use."To date, there really is no specific diagnosis that is caused by either keyboard computer use or smartphone use that we know of. So for example, just because you use smartphones doesn't mean you're likely to get carpal tunnel syndrome," said Dr. Aaron Daluiski, a clinician-scientist and surgeon at the Hospital for Special Surgery in New York.

"If it were specifically related to cell phone use or smartphone use, we would expect a surge in seeing a ton of additional patients in our office and doing many more operations per year because of the influx in use of smartphones over the past 10 years or so," he said. "We're just not seeing a dramatic uptick in incidence."Smartphone usage continues to grow around the world. In a 2015 Pew Research Center survey, 72% of Americans, 77% of Australians, 74% of Israelis, 88% of South Koreans and 71% of Spaniards reported owning a smartphone.Yet research has not been clear-cut on whether texting or general computer use are somehow related to hand and wrist problems, such as carpal tunnel syndrome, a condition that occurs when a nerve that runs from your forearm into the palm of your hand gets compressed at the wrist, leading to tingling sensations or itching numbness.

Study turns spotlight on texting, carpal tunnel trouble.What might contribute to hand problems such as carpal tunnel syndrome? The anatomy of your wrist; pre-existing health problems, such as a previous injury or rheumatoid arthritis; and possibly repetitive motions, like those associated with texting, Kakar said.Often, however, no single cause of carpal tunnel syndrome can be identified.A study published in the British Medical Journal in 2015 found no association between computer use and new cases of carpal tunnel syndrome.However, a 2015 study in the Journal of Neurological Scientists suggested that excessive computer use might be a minor risk factor for carpal tunnel syndrome.Now, a small study published in the journal Muscle and Nerve suggests that using electronic devices for more than five hours a day -- compared with using devices for five hours or less -- might adversely affect the nerve in your wrist known to play a big role in carpal tunnel syndrome.

The new study involved only 48 adults, 18 to 25 years in age, many of whom actually didn't report the classic symptoms of carpal tunnel, such as tingling or numbness in the thumb, index and long fingers. Rather, they reported having levels of pain in their hands and wrists.The adults completed questionnaires about how often they use electronic devices each day. The researchers analyzed their responses, conducted physical examinations and processed ultrasound images of their hands and wrists."Participants were asked about pain levels in our questionnaire, but the physical tests quantified presence of numbness and tingling," said Peter White, a co-author of the study and assistant professor at the Hong Kong Polytechnic University.The researchers found that those adults who reported using devices for five or more hours a day more frequently had enlarged and flattened median nerves linked to carpal tunnel syndrome, more frequently had positive clinical tests indicative of carpal tunnel syndrome and more frequently reported hand and wrist pain compared with those who used electronic devices less.

The study has limitations due to its small and relatively homogeneous sample size, self-reported data and relying on physical exams and ultrasound imaging rather than electro diagnostic testing to gauge hand and wrist health, White said."Therefore, additional exploration may be required for verification of these results," he said."Carpal tunnel syndrome is usually a condition affecting people of middle age, especially females, so our findings suggest a potential link between prolonged and intensive use of electronic devices by young adults and risk of injury, such as carpal tunnel syndrome."-A texting teen with tendinitisKakar, who was not involved in the study, described the study as interesting, despite some of its limitations."I think you'd be hard-pressed to have a direct linkage between too much electronic device time and carpal tunnel syndrome," he said of the study. "I don't think it's been proven by this, but it does raise awareness."

For smartphone users who have been diagnosed with carpal tunnel syndrome or have some hand or wrist pain, Kakar offered advice."Rather than texting all the time, you can use the many different voice applications in existence or simply try using different fingers to text," he said."Most of the time, when you have a tendonitis type of problem, hand therapy can help, but honestly, using (the device) less or in a 'smart' way may be the best way to go."One case study of a 14-year-old girl who said she texted four hours a day and developed tendinitis was published in The Journal of Family Practice in 2011. The girl not only was treated with a thumb spica splint and aspirin as needed, she modified her texting activity, according to the study. After about a month, she reported no longer suffering pain.

Some doctors point out that your hands and wrists are not the only body parts that may suffer due to too much texting.There's so-called "text neck," in which a cell phone user may feel soreness in the neck area from looking down at a handheld device screen for a long period of time. There's also what's being called "cell phone elbow," in which a person holds their elbow flexed for a prolonged period of time while using their phone, leading to some discomfort.All in all, Daluiski said, meeting with a health care professional if you have any hand and wrist problems or questions is important."Not all wrist pain is carpal tunnel syndrome. Carpal tunnel syndrome is a very specific diagnosis, where there's compression of the median nerve at the wrist and that produces pain but more numbness and tingling," Daluiski said."If patients have symptoms that are significant enough, that it's affecting their daily function, their daily sort of use of their hands, it's important to see someone, either their general practitioner or a hand therapist or a hand surgeon, to get an adequate diagnosis."