Flu Headaches – Causes, Dangers and Treatment

A headache is a common symptom with the seasonal flu. It usually lasts for a few days while the flu symptoms are the most intense. Some people have severe flu headaches while for others it may only be a minor ache. The pain gradually subsides after a few days along with other flu symptoms like fatigue, malaise, fever, a runny nose and a cough. A flu headache is usually not serious and is unlikely to lead to any complications.

Headache Only With the Flu

A flu headache as it is commonly referred to starts with the onset of the flu and subsides once the infection resolves. Often the headache is one of the earliest symptoms of the flu, accompanying other symptoms like fatigue, malaise (feeling of being unwell or a ‘sick’ feeling) and body aches. In other instances, a flu headache may only arise a day or two into the infection.

There are many possible causes of a headache. It is therefore important to differentiate between a flu headache and other types of headaches which may be triggered or worsen during the flu. Apart from starting when the other flu symptoms arise, a flu headache also resolves within a few days. This confirms that the headache was most likely due to the influenza viral infection and not some other cause.

Causes of the Flu Headache

The exact reason why a flu headache occurs is not always clear. The viral infection affects the entire body although it is primarily a respiratory tract infection. The body’s response to the virus is one factor that may contribute to the headache, apart from the action of the virus itself. However, several other factors may also be involved in the development of a flu-related headache.

Changes in blood pressure (hypo- or hypertension), low blood glucose (hypoglycemia) levels when not eating, dehydration possibly due to profuse sweating, neck muscle spasm and sleeping in an awkward position are some of the factors that can arise with the flu and contribute to a headache. Even these factors are short-lived. The headache will therefore stop once the infection resolves.

Dangers of a Flu Headache

Neurological complications from the seasonal influenza (flu) are rare but can occur. It may cause symptoms like seizures or weakness of the limbs in severe cases. This is more likely to be associated with certain strains of the influenza virus, like the H1N1 flu. A severe headache may also be present.

However, two brain-related conditions that may appear with flu-like symptoms are encephalitis and meningitis. Encephalitis is inflammation of the brain that is often due to an infection that is viral in nature. Meningitis is inflammation of the lining around the brain and spinal cord. It is also commonly caused by a viral infection.

A headache is a common and prominent symptom in both encephalitis and meningitis. The similarity of other symptoms with the seasonal flu leads many people to believe that they have the flu. The headache is also mistaken for the otherwise harmless flu headache. However, as encephalitis and meningitis worsen it becomes apparent that it is not just the seasonal flu.

It is essential that medical attention is sought as soon as possible. Both encephalitis and meningitis can lead to serious complications with permanent effects and even be life-threatening.

Headache Before and After the Flu

Sometimes flu headaches are not headaches caused by the influenza infection. Instead it may only be triggered or worsened during the flu. This is commonly seen among migraine sufferers.

A migraine attack is triggered by the flu and persists for days or even weeks after the flu infection resolves. Furthermore the pain may be more severe than is typically felt during other migraine attacks. Associated symptoms like light sensitivity and nausea are also exacerbated and compounded by the flu.

Another factor that can contribute to ongoing headaches after the flu is sinusitis. It is worse in people with pre-existing sinusitis for any reasons, be it allergic, infectious or due to other causes. The sinusitis worsens during the flu and persists thereafter, giving rise to headaches. Therefore a sinusitis headache or allergy headache may be ongoing.

Even other types of headaches, like tension-type headache or cluster headaches, may be triggered or worsened by the flu and will often persist after the flu.

Treatment for Flu Headaches

There is no cure for the flu or common cold. Medical treatment is not necessary for most cases of the flu. It is a short-lived infection that resolves on its own. A number of supportive measures can assist with coping with flu symptoms, reducing the duration and preventing complications.


Various drugs can help with the treatment and management of flu headaches and other flu symptoms. The most common drugs used during the flu are drugs like acetaminophen and ibuprofen. Both of these drugs have anti-inflammatory and analgesic properties which can help relieve a flu headache. Aspirin can also be used but should not be administered to children.


It is important to drink plenty of fluids. Large amounts of water and electrolytes can be lost through profuse sweating. It is exacerbated if vomiting or diarrhea occurs. Apart from increased water consumption, oral rehydrating solutions should also be consumed. These solutions have the optimal balance of fluid and electrolytes. It can prevent and treat dehydration headaches.


Avoiding or at least minimizing physical activity is also important. The body is undergoing strain as it combats the flu virus and further stress should be avoided. Bed rest can also help with the headaches by reducing the strain on the neck muscles. Lying in a dimly lit room may also help when the headaches are aggravated by light.


Heat therapy may also be helpful for relieving flu headaches. It can applied to the neck, upper back, side of the head (temples) or forehead. A heat bag or hot water bottle can be used but it should not be too hot due to the proximity to the brain and possible skin injury. Heat should be avoided if a person has a fever.

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