Steroid injections may be used when these methods have not changed the patient's symptoms. Patients who don't want to have surgery may choose this treatment option. A small amount of numbing agent mixed with a steroid is injected into the carpal tunnel.

Results of studies using steroid injections for CTS have been mixed. About half the patients get relief from symptoms and the other half do not. Researchers aren't sure why this happens. Studies are ongoing to try and find factors that would predict who gets better and who doesn't. Then doctors could select patients for steroid injection based on these factors.

For many patients, steroid injections give only temporary relief. If the needle giving the injection accidentally punctures the nerve, the patient can be left with permanent nerve injury. Studies comparing steroid injection to surgery show that patients have better short-term results with the injection. Long-term results (six months or more) show equal results.

For patients who can't have surgery due to other health concerns, steroid injection may be a good option. Patients who want to avoid surgery for any reason can usually have one to three injections safely. They may not get better, but if there are no complications, they won't be any worse.