Flu Headache: Why It Happens and How to Treat It
Key takeaways:
Headaches are a common flu symptom. They can be an early sign that you’re sick with the flu.
Flu headaches are brought on by fever, dehydration, and inflammation. Flu headaches are usually felt all over the head.
You can treat most flu headaches at home with over-the-counter (OTC) pain relievers, rest, and fluids.
Table of contents
During flu season, there are certain symptoms you just can’t ignore. Once you start coming down with a cough, fever, or fatigue, you know it’s time to stay home, see a healthcare professional, and start treating your flu symptoms.
But did you know that headaches are also a sign of flu illness? If you’re experiencing flu headaches, here’s what you can expect and what you can do to ease your symptoms.
Are headaches a symptom of the flu?
Yes. Headaches are a common flu symptom.
Search and compare options
Headaches tend to be an early sign that you’re coming down with the flu. They usually appear in the first 3 days of a flu illness, and they come on all of a sudden. But the biggest clue that you have a flu headache is that it begins at the same time as other flu symptoms, including:
Fever
Body aches
Fatigue
Dry cough
In classic studies, anywhere between 60% and 90% of people reported having a headache while they were sick with the flu. Interestingly, people with weakened immune systems were less likely to report having a headache.
What does a flu headache feel like?
A flu headache can feel like a dull or throbbing pain all over your head. Flu headaches aren’t mild. Most people describe them as being moderately painful. People may need to take a break from their activities because of flu headache pain.
Getting sick with the flu can also trigger a migraine. So, if you’re prone to migraines, you may experience more frequent or more intense migraines while you’re sick.
How does the flu cause headaches?
It’s not exactly clear why the flu causes headaches.
When is flu season? In the U.S., flu season usually lasts from October through May. Here’s what to expect this season.
Natural flu remedies: Headache is one of a handful of flu symptoms that can leave you feeling down. These home flu remedies can help.
Stages of the flu: Getting taken down by the flu is an unwelcome surprise. Here’s a flu timeline so you can know what to expect as you recover.
But there are several things that likely play a role:
Fever: People who’re sick with the flu often have a fever. Many people experience a headache when they have a fever.
Dehydration: When you have a fever, your body loses fluid faster than normal. If you don’t replace this extra fluid, you can develop dehydration. Dehydration is a common headache trigger. Many people don’t feel well when they have the flu. So, they might not feel up to drinking and develop dehydration quickly. This can then trigger a headache.
Cytokine release: When a person gets the flu, the immune system responds by releasing cytokines. Cytokines are chemicals that signal other infection-fighting cells to come help fight the virus. There’s some evidence that this cytokine release can cause headaches by triggering an inflammatory response in the structures around the brain.
Sinus congestion: Getting sick with the flu can cause a buildup of mucus in your nose and sinuses. Sinus congestion can cause painful pressure in the forehead and around the eyes, leading to a sinus headache.
How long does a flu headache last?
Flu headaches will get better within 3 to 7 days. It’s very rare to develop chronic headaches after having the flu. You should notice that your headaches gradually get better throughout your flu illness.
A headache that doesn’t go away after other symptoms get better could be a sign of a sinus infection. Headaches that are getting worse instead of better also need medical attention.
“A flu headache typically goes away when your other flu symptoms resolve,” according to Dr. Tracy Norfleet, a board-certified internal medicine physician and GoodRx contributor. “See your primary care provider if you have a lingering headache. It could be a sign of an infection or another medical condition.”
Remedies for a flu headache
Since flu headaches are short lived, you can usually treat them at home with over-the-counter (OTC) and home remedies. Here are some self-care treatments that can relieve your headache as you recover from the flu.
1. OTC pain relievers
Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) can help reduce fever and relieve headache. With acetaminophen, adults shouldn’t take more than 1,000 mg every 6 hours or more than 4,000 mg in a 24-hour period. The standard adult dose of OTC ibuprofen is 400 mg, with a max of 1,200 mg per 24 hours.
Taking too much pain-relieving medicine can actually trigger more headaches and lead to serious complications.
2. Fluids
Make sure to drink fluids to stay hydrated. This can help relieve and reduce headaches. Staying hydrated also helps your immune system work at its best so it can fight off the flu virus. Try drinking more water while you’re sick. Electrolyte sports drinks and broth are great options too.
But stay away from drinks with high caffeine and alcohol, which can worsen your dehydration.
3. Rest
It may sound obvious, but it’s important to give your body time to rest when you’re sick with the flu. You’ll want to get at least 7 to 9 hours of sleep per night. And take it easy while you’re awake. To get better sleep, try dimming the lights and lowering the volume of your television and other electronic devices.
4. Decongestants
If you have a stuffy nose, you can try OTC decongestants for 2 to 3 days. There are options you can take by mouth or as a spray in the nose. Some OTC options include pseudoephedrine (Sudafed) and oxymetazoline (Afrin) nasal spray. These decongestants can help relieve sinus pressure that could be contributing to your headache.
Keep in mind that you shouldn’t use decongestant nasal sprays for longer than 3 days or you can develop rebound congestion.
Flu headache vs. COVID headache
There are many types of headaches. And there are lots of possible causes beyond COVID-19 and the flu. So it can be hard to figure out what you’re dealing with.
Paying attention to the location and timing of your headache as well as any other symptoms you’re experiencing can give you important clues. For example, migraine headaches can cause sensitivity to light and sound, but this usually isn’t the case with a flu headache.
If you’re having lingering headaches, it’s a good idea to visit a healthcare professional. Some people get COVID and the flu at the same time. And unlike headaches from the flu, COVID illness can trigger chronic headaches. You may need a long-term treatment plan to help you manage COVID-related headaches.
When to see a doctor
For most people, the flu causes mild illness that can be treated at home. But some people have a higher risk of experiencing complications, such as pneumonia. The risk is higher for:
Young children
Pregnant women
Older adults
People with chronic medical conditions, such as asthma, heart disease, or diabetes
Keep in mind that the flu can cause severe symptoms in anyone. Here’s when to see a healthcare professional for the flu:
Symptoms aren’t improving, or they’re getting worse
Fever that doesn't get better
Trouble breathing
Cough that won't go away
Chest pain
Frequently asked questions
The general stages of a flu tend to follow a pattern, though everyone experiences the flu a bit differently. You’ll likely notice symptoms all of a sudden, and they may last about 3 to 7 days. Most people have a full recovery by 2 weeks.
The best way to prevent the flu is to get the flu vaccine. The flu vaccine is quite effective at preventing the flu, but you need to get it every year to stay protected.
If you do get the flu, and want to avoid flu headaches: stay hydrated, rest as much as possible, and consider OTC decongestants and pain relievers.
The flu can come on quickly and bring some uncomfortable symptoms, like nausea, fever, and body aches. Adding a headache on top of that makes for a rough time. To make matters worse, the flu can trigger a migraine for some.
The bottom line
Headaches are a common flu symptom. They usually start at the same time as other flu symptoms, and they get better within a few days to a week. Most flu headaches can be treated at home with OTC pain relievers, rest, and staying hydrated. See a healthcare professional for a headache that doesn’t get better with home treatment or doesn’t go away once you have recovered from your other flu symptoms.
Why trust our experts?
References
Arca, K. N., et al. (2021). Dehydration and headache. Current Pain and Headache Reports.
Better Health Channel. (n.d.). Influenza (flu). Victoria State Government.
Centers for Disease Control and Prevention. (2022). Clinical signs and symptoms of influenza.
Centers for Disease Control and Prevention. (2022). Flu symptoms and complications.
Eccles, R. (2009). Mechanisms of symptoms of common cold and flu. Common Cold.
Fischer, M. A., et al. (2023). Medication-overuse headache. StatPearls.
Li, D., et al. (2002). The clinical characteristics of new daily persistent headache. Cephalalgia.
Memoli, M. J., et al. (2014). The natural history of influenza infection in the severely immunocompromised vs nonimmunocompromised hosts. Clinical Infectious Diseases.
Monto, A. S., et al. (2000). Clinical signs and symptoms predicting influenza infection. Archives of Internal Medicine.
National headache Foundation. (n.d.). What your flu headache is telling you.
Pupanich, W., et al. (2012). A review on the clinical spectrum and natural history of human influenza. International Journal of Infectious Diseases.
Weber, J. R., et al. (2005). Headache attributed to infection. International Headache Society.
