Allergy headache causes, symptoms, & treatments

Reviewed by:
Dr. Robert Kwok
Director of Health Informatics
Last updated on May 16, 2022 UTC

There are many types of headaches, each with varying causes. For some people, a headache can be set off by an allergic reaction to airborne allergens and can be accompanied by a stuffy nose, itchy watery eyes, and sneezing.  

This article from HealthTap will break down how allergies can lead to a headache, which allergens can cause a headache, and what can be done to get relief. 

What is an allergy headache?

An allergy headache is an informal name given to a headache that’s brought on by allergies. It can refer to either a sinus headache or a migraine headache. 

Sinus headache 

The sinus cavities are air spaces inside the cheekbones, forehead, and midface bones. Allergies, viral infections, or bacterial infections can inflame them, making them swell up, produce extra mucus, and block the channels that drain them. 

If there is a build-up of mucus in the sinuses (sinus congestion), it can cause sinus pain that feels like a headache. The pain can be felt anywhere on the face, but tends to concentrate around the forehead, behind the eyes, and behind the cheeks. 

The facial pain is dull and tends to be mild to moderate in severity. It usually gets worse after lying down because this increases blood flow to the sinuses. 

Many people who have symptoms of sinus headaches may be having a migraine, while many others get diagnosed with allergic rhinitis (hay fever). There is overlap in the symptoms of these conditions.

Migraine headache 

Migraines are characterized by severe, throbbing pain that usually occurs on one side of the head. They can be accompanied by other symptoms like nausea and vomiting, and sensitivity to light and sound. 

Migraines are often set off by triggers, which varies tremendously among people. Examples of migraine triggers include obnoxious smells, high caffeine intake, rainy weather, or even changes in the menstrual cycle. In response to the trigger, there are changes in the brain’s blood flow which lead to the sensation of pain in the head and face.

A migraine can be preceded by an aura, which is a warning sign of sorts. Auras usually include visual changes, such as flashing lights or brightly-colored spots. About 25% of all migraines have an aura. 

So, what do airborne allergies have to do with migraines? 

Researchers are still trying to get to the bottom of this relationship. Most likely, the immune system (which is involved in allergies) is hypersensitive in those with migraines. This can cause inflammation in areas of the head, which can lead to severe pain sensations. 

Studies show that people with allergies, whether seasonal allergies or year-round, are more likely to have migraines. For instance, those who suffer from hay fever are four times as likely to have migraines.

Common allergy triggers 

Allergies are specific to the individual. However, there are a few culprits that affect a large portion of the population. Here are some of the most common allergy triggers.

Seasonal changes 

For millions of people across the world, spring means high pollen count, which is one of the most common causes of allergies. An allergy to pollen can lead to hay fever symptoms of extreme nasal congestion and an itchy runny nose. 

There are also other, less well-known seasonal changes that can cause allergies. Heat can make air pollution worse, which can be a trigger for some people. Humid days are another culprit because they increase moisture in the air, which makes mold (a common allergen) grow indoors and outdoors.

Dust mites

Dust mites are tiny organisms in dust that can only be seen with a microscope. A dust mite allergy is very similar to a pollen allergy, except that it occurs year-round, as opposed to just early spring and fall. 


Mold is a type of fungi that floats in the air like pollen and dust. They thrive in humid conditions and can be found in basements and bathrooms. For some people, touching or breathing mold can cause an allergic reaction. 

Pet dander

Pet dander refers to tiny pieces of skin shed by house pets — most commonly cats and dogs. When dander is inhaled by an allergic person, an allergic reaction may occur.

Food allergies 

Many food allergies can cause an immediate reaction, like indigestion. Some extreme forms of food allergies can even cause anaphylactic shock, a life-threatening condition in which the throat closes up. 

It is also possible for food allergies to cause no immediate reactions, but delayed ones. Symptoms such as brain fog, digestion problems, and skin disorders have been linked to food allergies

The most common food allergies include dairy, gluten, eggs, peanuts, and soy. Of course, everyone is unique, so it’s possible for less common foods to cause allergies. People who suspect a food allergy are usually advised to keep a food log where they keep track of their symptoms. 


Histamines are chemicals found in some foods and beverages, like wine. These chemicals are also produced in the body and cause allergy symptoms. 

Fermented foods (which includes alcohol) have high levels of histamine; nightshade vegetables (such as eggplants and tomatoes), dried fruit, and processed meats can also contain histamine. Consuming these foods can make allergies worse.

Treatment for allergy headaches 

If a headache is caused by a certain allergy, then removing the allergy is the first step in getting relief. Sometimes allergens — such as pollen — can’t easily be removed from the environment. Other times, the allergens causing symptoms may not be identifiable. 

Even if that’s the case, doctors can still treat the symptoms of an allergy headache to bring relief to the patient. Here are a few common treatment options and approaches.


As mentioned above, histamine is a type of chemical released when the body senses an allergen. Histamine causes uncomfortable allergy symptoms like watery eyes and itchy nose. 

Antihistamines are a type of medication that stops histamine from binding to cells in your body. This decreases the symptoms caused by histamine.

Antihistamines come in different forms, such as pills, eye drops, and nasal sprays. For eye symptoms, eye drops tend to work the fastest, bringing relief in minutes. Nasal sprays start working in less than an hour to decrease symptoms in the nose and sinuses, while pills take up to an hour to relieve symptoms throughout the body.

If you’ve taken antihistamine pills before, then you probably remember getting sleepy. This happens because histamine plays a role in wakefulness. A class of antihistamines called “first-generation” antihistamines usually cause sleepiness. One of the most common first-generation antihistamines is Benadryl (diphenhydramine).

It’s possible to avoid the drowsiness by sticking to” second-generation” antihistamines. These are just as effective at reducing allergy symptoms but without the sedative side effect, and include Zyrtec (cetirizine) and Claritin (loratadine). 

Nasal steroid sprays 

Inflammation is at the core of allergy symptoms because it causes swelling in the nose, sinuses, eyelids, and conjunctivae (the mucus membranes on the eyes). Corticosteroids (steroids) can help reduce this inflammation. 

Corticosteroids work by suppressing the immune response, which can then reduce inflammation. To treat allergies, corticosteroids are usually administered as a nasal spray. Even though this medication is administered in low doses, it’s important to take it for only a short period of time because it can have long-term side effects, such as irritation of the nose or throat. 

Steroid nasal sprays are available both over the counter and by prescription. They usually take about 6-12 hours to bring relief. Their full effects are generally felt after several days. 

Oral decongestants 

These medications work by narrowing blood vessels, which can then decrease the pressure and congestion in the nose and face. Decongestants usually come in pill or liquid form, and generally should not be taken for more than a few days. 

Nasal irrigation

Nasal irrigation is an effective option to naturally minimize sinus pressure. It involves using slightly salty water (saline) to rinse the nasal passages, and can be done carefully at home several times per day. A neti pot is a container that is specifically shaped to help make the nasal irrigation process easy.

Finding relief with HealthTap

If you’re experiencing allergy headaches or other allergy symptoms, then getting to the root cause is an important first step in finding relief. HealthTap can connect you to an affordable primary care provider who can treat allergy-based headache triggers and other chronic headache issues virtually so you never have to leave home.  

HealthTap provides online doctor visits to help with the diagnosis and treatment of allergies, migraines, and many other conditions. Over our secure platform, you’ll be able to discuss your symptoms, get diagnostic tests, and receive treatment through video visits. Our expert primary care providers will guide you every step of the way in your health journey. 

Get started with HealthTap today


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