The Connection Between Allergies and Headaches

Seasonal allergies—also called allergic rhinitis or hay fever—can cause itchy eyes, a runny nose, sneezing, or a cough. In some people, allergies can also cause headaches. There are several effective treatments, from home remedies to over-the-counter and prescription medications, that can keep your allergy symptoms at bay, including headache.

If you’re suffering from allergy symptoms or a headache of any kind, talk with your healthcare provider to determine possible causes and treatment. In this article, I’ll outline some allergy symptoms, including sinus headaches and migraines as symptoms of allergies.

I’ll also explore causes of allergies, and how to know if your headache is linked to allergies. Finally, I’ll cover how to treat allergy headaches, and other common causes of headaches. 

Symptoms of Allergies

When your body encounters a foreign object that it thinks could cause you harm, your immune system kicks in, releasing chemicals to fight it off. These chemicals, including one called histamine, can cause inflammation as part of the immune response.

When you have an allergic reaction, the body triggers an immune response to something that would otherwise be harmless—including different types of pollen, mold, pet dander, or dust. Allergies are a kind of overreaction to these substances.

For some people, symptoms are mild; for others, allergies can be severe and even fatal at times. 

Possible symptoms of allergies include: 

• Runny nose 
• Congestion 
• Itchy eyes 
• Sneezing
• Coughing
• Itchy skin or rash 
• Headache
• Itchy or scratchy throat

If you have asthma, seasonal allergies may trigger an attack that includes shortness of breath, wheezing, and coughing. Your asthma medication can reduce those symptoms, but you may need to treat the allergies, too. 

Sinus Headaches as a Symptom of Allergies

When allergens or other irritants enter your nose, your body forms mucus as a defense. Normally, mucus membranes drain out of your nose (which is why allergies can result in a runny nose for some people). If your mucus does not properly drain and you develop congestion, your sinuses may swell.

Inflammation in your sinuses can also result in swelling. Both these things can cause what many people call a sinus headache. Unlike other headaches, a sinus headache may cause pain or pressure around your sinuses.

This may include pain in your face, in the area surrounding your nose and your cheeks. You may also feel discomfort behind your eyes and in your forehead. 

Migraines as a Symptom of Allergies

A migraine is a severe, throbbing headache that’s often accompanied by other symptoms, such as nausea, vomiting, and sensitivity to light and sound. Allergies are a known migraine trigger.

A 2014 study found that migraines are more common in people who have seasonal allergies, and that seasonal allergies can lead to more frequent migraines. There are a few theories about the connection between allergies and migraines.

During the allergic response, your immune system creates inflammation in your body, which may result in a migraine. Allergies can also disrupt sleep—if you’re itchy or stuffy at night, it can be hard to get good rest. This allergy-induced sleep deprivation may also result in a migraine. 

Causes of Allergies

When your immune system is sensitive to something in the environment, you can develop an allergy. Different people are allergic to different things, including food, medications, and insect stings.

Seasonal allergies are typically caused by environmental triggers, such as: 

• Tree pollen 
• Grass pollen
• Ragweed pollen
• Mold
• Pet dander
• Dust mites
• Cockroaches

Different allergens are more common at different times: For example, in most U.S. regions, tree and grass pollen are higher in the spring and summer months, while ragweed is higher in the fall.

If you’re allergic to mold, pet dander, dust mites, or cockroaches—or if you live in a region where plants pollinate all year—you might also have winter allergies. Keeping track of your symptoms and their timing can help you pinpoint what you’re allergic to.

If needed, an allergist can also conduct a skin prick or blood test to determine the cause of your allergies. 

How to Know if Your Headache is Linked to Allergies

If you have pressure in your sinuses along with other allergy symptoms—and you know you suffer from seasonal allergies—it’s likely you have a sinus headache. If you have a severe headache and allergy symptoms, it’s possible you have a migraine induced by allergies. 

Still not sure? Your healthcare provider or a K doctor can help you determine the cause of your headache and recommend treatment. 

Treating Allergy Headaches

The best way to treat an allergy headache is to treat the allergies. Avoiding allergy triggers is one way to reduce your allergy symptoms and, in turn, stop a headache before it happens. 

Other treatments, including home remedies and medications, can help allergy headaches and overall allergy symptoms. 

Home remedies

• Drain out your sinuses: Flushing out your nasal passages with your nose with a saline rinse or using a neti pot can help clear allergens and mucus out of your nasal passages. This can help reduce pressure in your sinuses, which may improve the headache. Never use plain tap water for a sinus flush—follow instructions for safe sinus flushing here.

• Use a humidifier: Adding moisture to the air can also moisten your sinuses and improve their ability to drain mucus. If you don’t have a humidifier, try inhaling steam from a pot of boiling water or taking a hot shower. You might experience some relief from sinus pressure causing a headache.
  
• Apply a warm compress: A warm, wet cloth applied to your cheeks, nose, and forehead may help lessen inflammation in the area and soothe pain and pressure that’s built up in your nasal passages. 

• Smell an essential oil: Calming essential oils can help you relax, which comes in handy when you have a headache. Certain essential oils, research suggests, may actually have therapeutic properties that reduce allergy symptoms. For example, one study shows lavender essential oil can keep mucus cells from getting bigger and ward off inflammation. Both of these can help manage allergy headaches. 

Medications

• Antihistamines: These over-the-counter drugs stop the effects of histamine, the chemical that triggers allergy symptoms. Common antihistamines include loratadine (Claritin), cetirizine (Zyrtec), or fexofenadine (Allegra). Diphenhydramine (Benadryl) can is also an antihistamine, but it’s an older drug that has to be dosed more frequently and can result in more side effects, such as sleepiness.
  
• Nasal sprays: Nasal sprays that contain steroids can reduce inflammation in the nose, making it easier for mucus in your sinuses to drain. Some nasal sprays contain saline, which can help flush allergens from your sinus passages and reduce pressure that can cause a headache.
  
• Decongestants: Medications such as phenylephrine (Sudafed PE) or pseudoephedrine (Sudafed, Silfedrine, Suphedrin) work by reducing swelling in the sinuses, which can improve congestion and, as a result, a sinus headache. Decongestants also come in nasal spray form. While these medications work effectively and quickly, they can also cause dependence. 

• Non-steroidal inflammatory drugs (NSAIDs): Non-allergy drugs can also help reduce inflammation in your sinuses and reduce headache pain, along with treating migraines associated with allergies. NSAIDs such as ibuprofen (Motrin), aspirin, or naproxen (Aleve) can help. 

Other Common Causes of Headaches

Not sure if your headache is from allergies or something else? Your healthcare provider can help you determine which one may be contributing to your headache.

Non-allergy causes of headache include: 

• Sleep deprivation 
• Stress
• Alcohol consumption 
• Foods that contain nitrates (such as lunch meats)
• Poor posture
• Skipping meals 
• Hormonal changes, such as a person’s menstrual cycle 
• Infections, such as the common cold or COVID-19
• Sinus infection
• Dehydration
• Dental problems 
• Hypertension (high blood pressure)
• Overuse of headache medication, including prescription or over-the-counter medicines
• Anxiety and depression 
• Tight-fitting head gear, such as a hat, headband, or helmet

In rare cases, headaches may be caused by more serious issues. If you’re concerned about your headaches, they’re not responding to your usual treatment, or they’re getting worse, talk to your healthcare provider. 

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