You might’ve heard by now that it’s important to get a flu shot. It helps prevent the flu, and if you do get the flu, the shot can make symptoms less severe so that you feel better faster.

It’s also free to get, and it protects you as well as others — because if you’re protected against the flu, you can’t pass it on to someone else.

But sometimes you may feel sick the day after getting your flu shot. This is normal. Here, we’ll talk about common side effects of the flu shot.

Some people will feel fine after receiving their flu shot, but others may notice some side effects and symptoms. Generally, this is nothing to worry about and is often a sign that everything is working as expected.

Flu vaccines are very safe, but common side effects of the flu shot include:

Symptoms of the flu shot should subside within 1 to 2 days.

When to see a doctor

In rare instances, more serious adverse effects of the flu shot may occur. See your doctor if you:

  • have trouble breathing or are wheezing
  • notice vision changes
  • develop hives or a rash
  • have severe dizziness or fainting (not related to fear of needles)

Severe reactions are usually because the person is allergic to an ingredient in the vaccine, which is very rare.

Was this helpful?

If you’re feeling under the weather after receiving a flu shot, be sure to get plenty of rest. It can be helpful to treat the situation as if you do have the flu, which means it’s best to try:

You can also try an over-the-counter pain reliever to ease headaches or joint pain. Taking it easy should help you feel better quickly.

Side effects from the flu shot are not fun, but they’re worth it to protect yourself and at-risk loved ones from the flu. Flu vaccines are very effective, and they’re recommended for nearly everyone at or over the age of 6 months.

The flu shot is generally between 40 to 60 percent effective at preventing the flu. Even if you were to get infected, it greatly reduces the severity of illness.

A 2021 study showed that adults with an influenza-associated hospitalization who received a flu vaccine had a 26 percent lower risk of intensive care unit (ICU) admission and a 31 percent lower risk of death from the flu compared to those who did not receive the vaccine.

If you’re not feeling great after a flu shot, remember that it does not mean that you have the flu. Rather, it’s a typical immune response. This response is what helps teach your immune system to recognize and quickly respond to the flu virus should you encounter it in public spaces.

Barring rare exceptions, everyone at or over the age of 6 months should receive a flu vaccine. Side effects from the flu shot vary and may include a sore arm, fatigue, headache, or nausea.

While these can be unpleasant, it’s normal to experience flu-like symptoms in a day or two after receiving a flu vaccine, and it’s a natural immune response. Getting a flu vaccine every year is a great way to keep you and your family healthy.