The short answer. Carpal tunnel syndrome happens when the median nerve is squeezed as it passes through the wrist, causing numbness, tingling, burning and pain, mainly in the thumb, index, middle and ring fingers, and it often wakes people at night1. Symptoms usually start gradually and may travel up the forearm1. A rash is not among the symptoms listed by the American Academy of Orthopaedic Surgeons (AAOS), MedlinePlus or Cleveland Clinic1,2,3.
The carpal tunnel is a narrow passageway in the wrist, about an inch wide. Small wrist bones form its floor and sides, and a strong band called the transverse carpal ligament forms the roof. The median nerve runs through it along with the nine tendons that bend the fingers and thumb1. The median nerve provides feeling to the thumb, index finger, middle finger and the thumb side of the ring finger, and it controls the muscles at the base of the thumb1.
When the tunnel narrows, or the tissue around the tendons swells, pressure builds on the nerve and reduces its blood supply. That pressure causes the numbness, tingling, pain and weakness1. Carpal tunnel syndrome is the most common nerve entrapment worldwide4. In a Swedish study of 2,466 adults, 14.4% reported pain, numbness or tingling in the median nerve area of the hand, but only 3.8% were diagnosed with clinically certain carpal tunnel syndrome on examination5. Hand symptoms are common, and the researchers estimated that about 1 in 5 people with them would have carpal tunnel syndrome5.
AAOS lists these symptoms1:
Cleveland Clinic describes it as pinpricks, or fingers that feel as if they "fell asleep", with an urge to shake the hand out. The pain usually feels as though it comes from inside the hand or wrist rather than the skin, and it may be a sharp, burning stab or a constant ache3. Many people find that moving or shaking the hand helps1.
Symptoms usually begin gradually, without a specific injury, and at first they tend to come and go1. Night symptoms are very common, because many people sleep with their wrists bent1. During the day, symptoms often appear when you hold something for a long time with the wrist bent, such as a phone, a steering wheel or a book1. As the condition worsens, symptoms come more often and last longer1.
Yes. AAOS lists pain or tingling that travels up the forearm toward the shoulder1, and MedlinePlus lists pain that extends to the elbow2. In a study of 34 patients having carpal tunnel surgery, many reported symptoms beyond the thumb, index and middle fingers, including 33 reports in the front of the forearm. At 4 to 6 weeks after surgery, 32 of those 33 forearm symptoms had resolved6.
Similar symptoms can have other sources. Nerve testing can show whether the nerve is compressed somewhere else or whether another nerve condition is present1.
A rash is not a typical symptom. AAOS, MedlinePlus and Cleveland Clinic describe numbness, tingling, pain, burning and weakness, and none of them lists a rash1,2,3. Cleveland Clinic specifically describes the pain as coming from inside the hand or wrist, not a skin-level pain3.
Skin changes do appear in the medical literature, but rarely and in severe cases. A 2013 review names cutaneous manifestations of carpal tunnel syndrome among skin conditions linked to nerve damage7. A 2022 case report described a 69-year-old woman with moderate to severe carpal tunnel syndrome who developed skin ulcers on her fingertip; the authors noted that color changes, swelling and later hardening of the skin may also occur when the nerve's control of blood flow is impaired, and they called skin ulcers from carpal tunnel syndrome rarely reported8. These are ulcers and color changes in advanced disease, which is different from an ordinary itchy rash.
Because a rash is not a recognized symptom, a rash on the hand or wrist is worth having examined on its own terms.
MedlinePlus states that studies have not proved carpal tunnel syndrome is caused by typing on a computer or using a mouse, though these activities may cause tendinitis or bursitis that can narrow the tunnel2.
Symptoms can show up during the day with repeated motions such as typing3. MedlinePlus suggests keeping the keyboard low enough that the wrists are not bent upward, taking frequent breaks, and stopping if you feel tingling or pain2. Using hand tools that vibrate, such as drills or hammers, may also lead to carpal tunnel syndrome2.
Most cases come from a combination of factors, and women and older people are more likely to develop it1. Other risk factors include1:
MedlinePlus adds wrist fractures and arthritis, a cyst or tumor in the wrist, obesity, and amyloidosis to the list2.
In many cases, a doctor can diagnose carpal tunnel syndrome from your history and a physical exam alone1. The exam may include tapping over the nerve at the wrist to see whether it causes tingling (Tinel's sign), holding the wrist bent to see whether numbness or tingling appears, testing feeling in the fingertips, and checking the muscles at the base of the thumb for weakness or wasting1.
In some cases, other tests are needed1:
AAOS says that when carpal tunnel syndrome is diagnosed and treated early, the symptoms can often be relieved without surgery1. When symptoms are mild or the diagnosis is not yet clear, nonsurgical treatment comes first1. AAOS lists these options1:
Research reviews add some detail:
If nonsurgical treatment does not relieve symptoms, or relieves them only for a time, your doctor may recommend surgery1. The decision rests on how severe the symptoms are, the exam findings, how the symptoms have responded to nonsurgical care and the test results1. In long-standing cases with constant numbness and wasting of the thumb muscles, surgery may be recommended to prevent permanent damage1.
The operation, called carpal tunnel release, cuts the transverse carpal ligament that forms the roof of the tunnel. This makes the tunnel larger and takes pressure off the median nerve1. It is usually done as an outpatient procedure1. It can be done through a small incision in the palm (open release) or with a miniature camera through smaller incisions (endoscopic release), and AAOS says the outcomes of the two are similar1.
AAOS says that for most patients, surgery will improve the symptoms of carpal tunnel syndrome1. After surgery, night symptoms improve dramatically in the first week or so for most patients. Grip and pinch strength usually return in 2 to 3 months, and complete recovery can take up to a year1. As with any operation there are risks; the most common complications AAOS lists are bleeding, infection, wound healing problems and irritation of or injury to a nerve1.
AAOS notes that in most patients carpal tunnel syndrome gets worse over time, and that if it goes untreated for too long it can lead to permanent loss of feeling and weakness in the hand1. MedlinePlus advises contacting a provider if symptoms continue despite regular treatment, if the fingers lose more and more feeling, if there seems to be a loss of muscle bulk, or if you are dropping things2.
Numbness and tingling in the hand can come from more than one cause, and an orthopedic evaluation can help sort out which one it is. To arrange an evaluation, call (805) 682-1394.
Short answers to the questions patients ask most.
Have a question about your own situation?
Call (805) 682-1394Many people sleep with their wrists bent, which can bring on symptoms and wake them up1.
Yes. MedlinePlus lists symptoms in one or both hands2.
It can improve with rest or by avoiding repetitive wrist motions, but Cleveland Clinic says it is much more likely not to heal without diagnosis and treatment3.
Reviewed by Dr. Richard Scheinberg, MD, a board-certified orthopedic surgeon in Santa Barbara with 40 years of surgical experience.
