It's normal and common for your arm to be sore after getting a flu shot. Your symptoms may include pain, swelling, or redness where the shot was given. This happens because of the injection itself ...

Brachial plexus injury, affecting nerves controlling the arm, can cause severe pain, numbness, weakness, or paralysis. Early ...

Should I stretch my arm if it hurts? Being sore and in pain are two different things. If your arms are sore from overuse or poor posture, stretching may actually help improve your condition.