Can Allergies Cause Swollen Lymph Nodes

By Latifa deGraft-Johnson, MD
Medically reviewed checkmarkMedically reviewed
September 27, 2022

Sneezing, watery eyes that itch, and a runny nose are often a sign of allergies. But when you also notice swollen lymph nodes anywhere in your body, you may wonder if something more serious is going on. Take a deep breath.

Although you may not associate the two, any kind of allergies (including seasonal allergies, environmental allergies, and food allergies) can sometimes cause lymph nodes to swell. 

In this article, I’ll first explain what lymph nodes are and how allergies can lead to swollen lymph nodes. Then I’ll discuss ways to treat swollen lymph nodes at home and when you should see a doctor.

What Are Lymph Nodes?

Lymph nodes are small, bean-shaped structures that are a part of your lymphatic system (also called the lymph system), which is part of the immune system.

There are hundreds of lymph nodes throughout the body—in the neck, groin, armpits, and more—and they are connected to each other by lymph vessels. 

Lymph vessels carry lymph fluid (a clear, watery substance that contains white blood cells, proteins, and fats) to the lymph nodes.

The lymph nodes act as filters for foreign substances, destroying germs, viruses, and bacteria that enter the body. Though they’re often called lymph glands, lymph nodes are not glands.

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Why do lymph nodes swell?

Lymph nodes fill with excess lymphatic fluid and swell any time the immune system needs to remove harmful substances.

The most common reason for swelling is because the body is fighting a bacterial infection or viral infection, but swelling can also occur due to: 

  • Immune system disorders (such as lupus)
  • Immune system reactions (such as to medicines or allergens)
  • Stress
  • Cancers

Can Allergies Cause Swollen Lymph Nodes?

While it’s not a common symptom of allergies, lymph nodes may swell because of an allergic reaction.  Any allergen—such as pollen, dust mites, mold, or animal dander—is a foreign substance in the body and therefore triggers an immune response.

This allergic response can in turn trigger the lymphatic system and lead to swollen lymph nodes.Because allergies weaken the immune system, making the body more susceptible to viruses and bacteria, secondary infections such as sinus infections or upper respiratory infections may also occur.

These infections can cause swollen lymph nodes as well.

How to Treat Swollen Lymph Nodes from Allergies

Though swollen lymph nodes from allergies can be tender and uncomfortable, you can find relief with treatments such as those below.    

Take allergy medication

Allergy symptoms such as runny nose, cough, nasal congestion, sore throat, and itchy eyes are caused by a chemical called histamine. The body produces histamine because it thinks the allergen is harmful to the body. 

As the name implies, antihistamines help reduce allergy symptoms by blocking histamine. In turn, the medication may help reduce the swelling of lymph nodes. Antihistamines are available over the counter and by prescription. 

Apply a warm compress

A warm compress may help relieve pain when applied to swollen lymph nodes. You can create a compress by dunking a clean cloth in warm water and then wringing it out.

Get adequate sleep

A good night’s sleep is essential for keeping the body and all its systems—including the lymphatic system—functioning properly.

It can also keep the immune system strong to reduce the likelihood that you experience a secondary infection as a result of allergies. 

Stay hydrated

Proper hydration is another essential part of maintaining a healthy immune system. For people ages 19-30, the National Academy of Medicine suggests a daily water intake of at least 16 cups for people with penises and 11.5 cups for people with vaginas.

However, the exact intake varies based on age, physical activity level, climate, and any current medical condition. Your healthcare provider can guide you.

Take an over-the-counter pain reliever

Though they won’t reduce the swelling, over-the-counter (OTC) pain medications like ibuprofen (Advil, Motrin) and acetaminophen (Tylenol) can help lessen the pain and tenderness associated with swollen lymph nodes.

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When to See a Doctor

While most swollen lymph nodes are not considered serious and go away on their own within a couple of weeks, if you experience any of the following, see a doctor as soon as possible:

  • Lymph nodes that don’t go away or continue to grow after several weeks
  • Lymph nodes that are red and tender
  • Lymph nodes that feel hard or fixed in place (you should be able to slightly move the lymph nodes)
  • Fever, night sweats, or unexplained weight loss
  • Your child has lymph nodes larger than one centimeter in diameter

How K Health Can Help

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Check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes. 

K Health’s AI-powered app is based on 20 years of clinical data.

Frequently Asked Questions

Can seasonal or environmental allergies cause my lymph nodes to swell?
Yes, seasonal and environmental allergies may cause lymph nodes to swell. Allergens trigger the immune system, which in turn triggers a response from the lymphatic system. When this happens, the lymph nodes fill with fluid that contains white blood cells to fight the foreign substance (in this case, the allergen). The additional lymph fluid causes lymph nodes to swell.
How serious is a swollen lymph node?
Swollen lymph nodes are not inherently dangerous. They can, however, indicate a more serious underlying issue such as an infection, immune disorder, or, in rare cases, cancer. See a medical provider if you are concerned about a swollen lymph node.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Latifa deGraft-Johnson, MD

Dr. Latifa deGraft-Johnson is a board-certified family medicine physician with 20 years of experience. She received her bachelor's degree from St. Louis University, her medical degree from Ross University, and completed her family medicine residency at the University of Florida. Her passion is in preventative medicine and empowering her patients with knowledge.