The Real Reason Your Arm Hurts After Getting A Flu Shot

If you've ever wondered why your arm hurts after getting a flu shot, look no further. Soreness or pain in the arm and shoulder area is caused by inflammation (via Mental Floss).

When the flu vaccine is injected into the muscle of your arm, your body is exposed to an antigen — a dead or inactive version of the influenza virus. This dead virus will not give you the flu, but it will trigger an immune response, allowing your body to produce antibodies to fight off infection. This response causes inflammation, leading to soreness near the injection site.

While arm pain is a fairly common and completely harmless reaction to the flu shot, not everyone who gets vaccinated will experience it. If your arm doesn't hurt after getting the flu shot, that doesn't mean the vaccine isn't working. It just means that different people have different responses and reactions to the vaccine.

While soreness in the arm after getting vaccinated is typically minimal and should only last a day or two, there are some steps you can take to help ease the pain. One way to minimize any discomfort or soreness is to take pain relievers (via Today). Take a low dose of ibuprofen, naproxen, or acetaminophen either before or after getting the flu shot. This will help relieve any soreness in the arm.

Another solution is to drink plenty of water. "Any degree of dehydration is going to exacerbate that muscle tension," Dr. Jake Deutsch, the clinical director of Cure Urgent Care, told Today. You can also massage your arm and shoulder area or apply a cold compress.

While it may be uncomfortable, arm soreness should not deter you from getting a flu shot. The flu vaccine is safe and effective and is ultimately important for the health and safety of yourself and those around you.