The tetanus shot is an immunization that protects against a serious bacterial infection. While highly effective, it commonly leads to localized arm soreness at the injection site. This discomfort is a normal response as your body builds protection.
Typical Duration of Soreness
Arm soreness following a tetanus shot typically lasts for a few days. Most individuals report that pain, redness, or swelling at the injection site subsides within one to three days. The intensity of discomfort can vary, with some experiencing mild tenderness and others feeling more noticeable soreness. This localized reaction usually begins within a few hours of vaccination.
Individual responses can influence the exact duration of soreness. While most find relief quickly, a small number might experience symptoms for a slightly longer period. The Centers for Disease Control and Prevention (CDC) notes that injection site pain occurs in about two out of three adults receiving the Tdap vaccine.
Why Your Arm Gets Sore
Soreness after a tetanus shot results from your body’s immune system responding to the vaccine. The tetanus vaccine contains a weakened version of the toxin produced by Clostridium tetani bacteria, known as a toxoid. When injected, typically into the deltoid muscle of the upper arm, it triggers a localized inflammatory response.
This inflammation involves the recruitment of immune cells to the injection site. These cells recognize the toxoid and begin producing antibodies, which protect you if you encounter the actual tetanus bacteria. The immune system activation and slight tissue displacement from the injected fluid contribute to soreness, redness, and swelling.
Managing Arm Soreness
Steps can help alleviate discomfort after a tetanus shot. Applying a cool compress or ice pack to the injection site can reduce swelling and pain. Do this in short intervals throughout the day after receiving the vaccine.
Gentle movement of the vaccinated arm aids in dispersing the vaccine fluid within the muscle, which can lessen soreness. Simple exercises like arm circles or shoulder shrugs promote blood flow and reduce stiffness.
Over-the-counter pain relievers such as acetaminophen or ibuprofen effectively manage pain and reduce inflammation. Avoiding strenuous activity with the affected arm immediately after the shot can prevent increased discomfort.
When to Be Concerned
While arm soreness is normal, certain signs warrant medical attention. Seek advice if pain, redness, or swelling at the injection site worsens or persists significantly beyond a few days. Spreading redness, especially if it extends far beyond the injection site, or severe pain that hinders normal activities, should prompt a medical evaluation.
Other indicators for concern, which could signify a rare but serious allergic reaction, include:
High fever
Hives
Difficulty breathing
Swelling of the face or throat
Dizziness
Rapid heartbeat
Though uncommon, conditions like severe arm pain lasting weeks or months, or deep, aching pain with muscle weakness, could indicate a more serious issue such as a shoulder injury related to vaccine administration (SIRVA) or brachial neuritis. Consult a healthcare provider if you experience any concerning or unusual symptoms after your tetanus shot.