Carpal tunnel syndrome is a common condition that affects the wrist and hand, leading to discomfort and functional limitations. It arises from pressure on a major nerve in the wrist, known as the median nerve. Many individuals experiencing symptoms in one hand often wonder if the condition can also develop in the other hand.
Understanding Bilateral Carpal Tunnel
Carpal tunnel syndrome can affect both hands simultaneously, known as bilateral carpal tunnel syndrome. It is common, affecting approximately 60% to over 80% of individuals diagnosed with carpal tunnel syndrome, even if symptoms are initially noticed in only one hand. It may manifest in one hand first and then the other, or develop simultaneously in both wrists.
The carpal tunnel is a narrow passageway in the wrist, formed by carpal bones and a strong band of connective tissue called the transverse carpal ligament. This tunnel houses the median nerve and nine tendons that facilitate finger and thumb movement. When the space within this tunnel narrows or the tissues surrounding the tendons swell, it compresses the median nerve, leading to carpal tunnel symptoms.
Identifying the Symptoms
Symptoms of carpal tunnel syndrome often begin gradually. These commonly include numbness, tingling, burning, and pain, primarily affecting the thumb, index finger, middle finger, and the thumb-side of the ring finger. These sensations can feel like “pins and needles” and may radiate up the forearm towards the shoulder.
Symptoms are often worse at night, waking individuals from sleep, as bent wrists increase pressure on the median nerve. During the day, symptoms may worsen with activities involving prolonged wrist flexion or extension, such as driving or holding a phone. Weakness and clumsiness in the affected hand or hands, making fine movements difficult or causing objects to be dropped, can also develop as the condition progresses.
Common Causes and Risk Factors
A combination of factors contributes to carpal tunnel syndrome, especially when it affects both hands. Repetitive hand and wrist movements, such as typing, assembly line work, or using vibrating tools, can irritate wrist tendons and cause swelling that compresses the median nerve. Prolonged wrist extension or flexion can also increase pressure on the nerve.
Medical conditions increase the likelihood of developing bilateral carpal tunnel syndrome. These include diabetes, which can lead to nerve damage and fluid retention, and thyroid dysfunction, particularly hypothyroidism, associated with fluid retention and tissue swelling. Inflammatory conditions like rheumatoid arthritis can cause inflammation in the synovium, the lining around tendons, leading to swelling within the carpal tunnels. Pregnancy is another common risk factor due to hormonal changes that cause fluid retention and swelling, though symptoms often resolve after delivery. Anatomical factors, such as smaller carpal tunnels, and obesity can predispose individuals to the condition.
Treatment Options
Treatment for carpal tunnel syndrome, whether unilateral or bilateral, begins with conservative approaches. Wearing a wrist splint, especially at night, helps keep the wrist in a neutral position to reduce pressure on the median nerve. Activity modification, adjusting tasks that aggravate symptoms, and physical therapy, including nerve gliding exercises, can also be beneficial. Over-the-counter pain relievers, such as ibuprofen or naproxen, may offer short-term pain relief.
When conservative methods are insufficient, medical interventions may be considered. Corticosteroid injections directly into the carpal tunnel can reduce inflammation and swelling, providing temporary symptom relief. These injections are often recommended for mild to moderate cases. If symptoms are severe or do not respond to other treatments, surgical decompression, known as carpal tunnel release, may be recommended. This procedure involves cutting the transverse carpal ligament to enlarge the carpal tunnel and relieve pressure on the median nerve.