Side effects of nerve blocks include pain at the injection site, high blood sugar, itching and skin rashes, explains WebMD. Individuals treated with nerve blocks may also experience weight gain. In rare instances, nerve block medications can be life-threatening.
Individuals who receive nerve-blocking medications in the stellate ganglion nerves of the neck may experience side effects such as drooping eyelids, swallowing difficulty and vocal changes, explains Johns Hopkins Medicine. These side effects are temporary, and patients should eat and drink carefully until full swallowing is restored.
Additional side effects of nerve blocks include nerve injuries, infection and bleeding, explains the University of Maryland Rehabilitation and Orthopaedic Institute. When nerve blocks are utilized to block pain during an operation, temporary numbness along the injection site and temporary weakness are common side effects that occur after the procedure. These side effects usually resolve within a few hours' time.
Side effects of corticosteroid anesthetic nerve block injections that are used to treat chronic pain due to conditions such as sciatica or herniated discs include fluid retention, hot flushes and mood fluctuations, explains Mayfield Clinic for Brain & Spine. Individuals with current infections, pregnant women and those with bleeding disorders should not receive corticosteroid shots. Patients typically begin to experience decreased pain within two to seven days following the treatment, but a second injection may be required if pain levels do not improve after 10 days' time.