Tired? You May Be Experiencing Allergy Fatigue

When you hear the word “allergies,” you probably think of itchy eyes, a runny nose and uncontrollable sneezing — all things you’d expect to happen when your body’s trying to expel an allergen.

But what about feeling tired and fuzzy-headed? Why does that happen?

Allergist and immunologist Mark Aronica, MD, explains the relationship between allergies and fatigue.

The allergy-fatigue connection

Allergies cause fatigue because, for starters, your immune system expends a lot of energy responding to the thing you’re allergic to.

“Your body produces something called cytokines whenever you’re exposed to an allergen, like tree pollen, grass or mold,” Dr. Aronica says. Cytokines are proteins your immune system releases to help your body fight foreign substances. The cytokine release — paired with the release of other chemicals, like histamine — causes inflammation in your nose, leading to congestion and narrowed airways.

“You also produce them when fighting infections caused by bacteria, viruses and colds,” he notes.

During an allergy attack, your body is focusing its energy on responding to what it perceives as a threat, just like it does when you’re sick in bed. That’s why allergies make you tired: Mounting that immune response isn’t easy!

“People with allergies experience inflammation,” Dr. Aronica says. “That inflammation leads to nasal congestion, disrupted sleep patterns and not getting good rest.”

Allergies and brain fog

Fatigue isn’t the only symptom that can leave people with allergies stumbling through their day: Many also report struggling with “brain fog” — a hazy, tired feeling that makes it difficult to concentrate.

Dr. Aronica says brain fog is another side effect of allergy fatigue.

“Chronic inflammation from allergies can lead to that foggy feeling,” he explains. “The more fatigued you are, the more difficulty you’ll have performing well in school or work. It can also negatively impact your quality of life if you’re too tired to do things you would normally do, like work out.”

Poor sleep

In a particularly cruel twist of fate, the same allergic reaction that makes you so tired can also make it more difficult to get the rest you need. That’s because histamines and cytokines play a vital role in regulating your body’s sleep-wake cycle. When an allergic reaction throws that delicate balance off, it can make it harder to fall and stay asleep.

In this way, allergy fatigue creates a vicious cycle. It interrupts your schedule during the day, which robs you of precious sleep at night. If, for example, you drink cup after cup of coffee just to get through your workday, you may find yourself buzzing at night, when you should be catching ZZZs.

Medications

Certain antihistamines — both over-the-counter and prescription — can cause drowsiness, making allergy fatigue even harder to shake.

Generally speaking, “second generation” antihistamines (like loratadine, fexofenadine and cetirizine) are less likely to make you sleepy. That’s because they were designed not to cross the blood-brain barrier as easily as their “first generation” forbears (like diphenhydramine, chlorpheniramine and hydroxyzine).

But even second-generation antihistamines can make you sleepy if:

• You take other medications: The more medications you’re taking at once, the greater the chances they’ll interact, causing side effects.
• You drink alcohol: It’s never a good idea to mix antihistamines and alcohol, but it’s extra dangerous if you’re using first-generation antihistamines. In addition to the powerful sedative effects, this combination can cause dizziness, confusion, liver damage and more.
• You’re unlucky: Medications affect all of us differently. It’s possible you just drew the side effects short straw.

If you think your medication may be contributing to allergy fatigue, ask your doctor or pharmacist about switching to another one — or whether it’s safe to take the medication before bed.

What you can do about it

If your allergies act up and you feel the fog rolling in, Dr. Aronica says that a combination of medical treatments and lifestyle changes may help end the uncomfortable cycle of symptoms, inflammation and fatigue. He recommends that you:

• Know your triggers. Work with your provider to determine what exactly you’re having an allergic reaction to. Even if you don’t get formal allergy testing, keeping a symptom journal can help you determine what’s fueling your allergies and, in turn, your fatigue.
• Don’t bring the outdoors in. “If you’re allergic to pollen or grasses, try to stay away from them,” Dr. Aronica advises. “Stay indoors when they’re at their peak. Keep your windows closed if you can. And if you do spend time outside, shower and change your clothes as soon as you come in.”
• Take care of your pets. They may be cute, but your pets can also be dander factories. Limit your exposure to allergens (including the ones they pick up outside) by regularly grooming your pets, machine washing their beds and giving them a good wipe down after potty trips.
• Take allergy medicine. “Oral antihistamines are a temporary solution, but they are often effective,” says Dr. Aronica. Over-the-counter and prescription steroid nasal sprays can also help combat allergy symptoms. If your medication’s making you sleepy, tell your provider.
• Consider allergy shots. Allergy shots, or immunotherapy, can be an effective treatment for persistent allergy symptoms. Small injections of allergens under the skin can help your body build up immunity over time. The result is less frequent and less severe allergic rhinitis.
• Try nasal irrigation. Dr. Aronica says some people find temporary allergy relief with nasal irrigation — a saline wash (usually done with a neti pot) that cleans out the sinuses and nasal passages. Just be sure to use distilled or filtered water and clean it after every use.
• Use the right eye drops. If you can’t stop pawing at your red, itchy eyes, try artificial tears. The antihistamines in anti-redness and allergy eye drops may help in the moment, but they can also cause dryness, irritation and — if you overuse them — a rebound effect.
• Focus on sleep hygiene. Going to bed and waking up on a consistent schedule, banishing blue light and avoiding stimulants like coffee or tea before bed won’t cure your allergies. But it will make whatever sleep you get more restful and restorative.

When to talk to your doctor

Contact your primary care provider or an allergist if your allergy fatigue and brain fog aren’t improving. You may need additional testing or treatment.

Dr. Aronica also notes that there are other medical conditions that can cause fatigue and brain fog. Pay special attention to these symptoms:

• Sore throat
• Cough
• Fever
• Body aches

“You could have a cold or another upper respiratory illness,” he says. “If that’s the case, you’ll need to take different medications to combat your symptoms.”

With your provider’s guidance and a little trial and error, chances are good that you’ll be able to get a handle on your symptoms — and save zombie-mode for Halloween.