I have numbness (a needles-and-pins sensation) in my fingers and have been diagnosed with carpal tunnel syndrome (CTS). My doctor told me it was triggered by my pregnancy. Is there any truth to that that? Where does the syndrome come from and what is the treatment? - C.C., by e-mail. Dr. Carol Pidhorz, a senior hand surgeon at Hadassah University Medical Center in Jerusalem's Ein Kerem, replies: Carpal tunnel syndrome (CTS) is a widespread condition that results from the median nerve - which runs from the forearm into the hand - being squeezed or pressed at the wrist. The median nerve controls sensations to the palm side of the thumb and three of the four fingers and some small hand muscles that enable the fingers and thumb to move. The carpal tunnel is a narrow, rigid passageway of ligament and bones at the base of the hand. It envelops the median nerve and tendons. It may thicken from irritated or inflamed tendons, which narrows the tunnel and causes the median nerve to be compressed. This can result in weakness, pain or numbness in the hand and wrist (as you describe), radiating up the arm. Although painful sensations may indicate other conditions, CTS is the most common condition in which the peripheral nerves are compressed or traumatized. Symptoms usually start gradually at night, but as they worsen, people might feel tingling during the day. It may become difficult to grasp small objects or carry out other manual tasks or be unable to tell the difference by touch between hot and cold. As some people have smaller carpal tunnels than others, congenital factors may be involved. However, CTS does not run in families or have a genetic component. Environmental factors include repeated use of vibrating hand tools, such as air hammers; trauma or injury to the wrist that cause swelling, such as sprain or fracture; overactivity of the pituitary gland; hypothyroidism; rheumatoid arthritis; mechanical problems in the wrist joint; work stress; or hormone changes and fluid retention during pregnancy or menopause. In some cases no cause can be identified. Although many believe that repetitive use of the computer mouse is responsible for most cases of carpal tunnel there is little clinical data to prove this. Repeated motions performed in the course of normal work or other daily activities can result in repetitive motion disorders such as bursitis and tendonitis. CTS has become more common because of longer life expectancy as well as professions that involve vibrations, such as the use of hammers or placing floor tiles, which have to be tapped. CTS rarely occurs in children. Women are about three times more likely than men to develop CTS than men, apparently because the tunnel is usually smaller in women than in men. The dominant hand is usually affected first and produces the most severe pain, but not always. In most cases, both hands are affected by CTS. People with diabetes or other metabolic disorders that affect the nerves and make them more susceptible to compression are also at high risk. Pregnancy may indeed trigger CTS. After pregnancy, the symptoms usually fade away, but they may return with a subsequent pregnancy. If this occurs, this is often a sign that it will not go away. When the sufferer is a pregnant woman, doctors usually take the conservative approach using physiotherapy or a supporting brace for the hand rather than drugs or surgery. In others, cortisone injections may be given to bring down the inflammation. Ice doesn't help, but heat may alleviate the symptoms somewhat. Sometimes, non-steroidal drugs can help, but only for a short time, in alleviating pain. If nothing else works, surgery is performed, and this is usually considered a cure as rarely does CTS condition after an operation. The surgery, which is very safe and takes only 15 to 20 minutes, increases the size of the carpal tunnel by 50 percent. It is given with a local anesthetic and sedation, rather than general anesthesia. About two or three weeks after surgery, the patient can resume his normal life. Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to firstname.lastname@example.org, giving your initials, age and residence.