People have lymph nodes, commonly called lymph glands, throughout their bodies. Research suggests that swollen lymph nodes can be a side effect of COVID-19 vaccination or a symptom of the illness.

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Doctors also refer to the swelling of lymph nodes as lymphadenopathy.

This article explores the possible links between COVID-19 vaccination and the illness itself with swollen lymph nodes and additional symptoms. It also looks at other causes of swollen lymph nodes, home remedies, and when to contact a doctor.

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub for the most recent information on the COVID-19 pandemic.

Researchers have established a link between swollen lymph nodes and COVID-19, both as a side effect of vaccination and a symptom of the condition.

As a vaccine side effect

Developing swollen lymph nodes in the armpits is a documented side effect of receiving two doses of a messenger RNA (mRNA) vaccine for COVID-19.

The Pfizer and Moderna vaccines are both mRNA versions of COVID-19 vaccines that are widely available in the United States.

Developing swollen lymph nodes after receiving an mRNA vaccination is fairly common and may signal an immune response to the vaccine. In a recent study, 44% of participants experienced it, with the condition lasting for up to 43 weeks after COVID-19 vaccination.

Researchers demonstrated that swollen lymph nodes were more frequent in people who had received the Moderna vaccine than those who had the Pfizer vaccine.

Typically, a person may only be able to feel their swollen lymph nodes for about 10 days after vaccination. However, they may still appear on mammograms, looking similar to warning signs of breast cancer, for up to 1 month after vaccination.

Some medical professionals recommend that people schedule mammograms for at least 1 month after they receive their mRNA vaccines, if possible.

As a COVID-19 symptom

Swollen lymph nodes may occur in anyone with a post nasal drip, which is an excess of mucus down the back of the throat. The swelling usually indicates a common infection, such as a cold or flu, but can also be a sign of other conditions.

A 2022 study documents cases where people who had swollen lymph nodes in the neck and behind the ear but did not have any respiratory symptoms received a diagnosis of COVID-19.

Swollen lymph nodes on the neck are also one of the symptoms associated with multi-system inflammatory syndrome in children (MIS-C). MIS-C is a rare but serious condition that can develop in children exposed to COVID-19.

MIS-C can develop several weeks after COVID-19 exposure and progress rapidly, requiring critical care. If a child complains of neck pain, a parent or caregiver should monitor their condition closely. They should seek medical care immediately if abdominal pain, chest pain, or other symptoms also develop.

When a person has swollen glands due to a common virus, they may feel generally unwell as the body is fighting off an infection of some sort.

Other symptoms that may develop around the same time as the swollen lymph nodes include:

Although the number of cases and studies are limited, researchers have found that if a person with COVID has swollen lymph glands, they may also have some other characteristics, such as:

In addition to the connection with COVID-19, many other factors can cause swollen lymph nodes. The most common are:

More serious and less common causes include:

Cancer can also cause swollen lymph nodes. However, this is very rare.

Most of the time, even if swollen lymph nodes develop after receiving a COVID vaccine, a person can handle this condition at home.

People can use warm compresses or heating pads to ease soreness in swollen areas. Over-the-counter (OTC) pain relievers such as ibuprofen or acetaminophen can also help reduce discomfort. Doctors recommend people stay hydrated and rested during the recovery period.

However, if an underlying medical condition is responsible for lymph node swelling, treatment with prescription or OTC medications can help reduce the swelling.

Most of the time, swollen lymph nodes return to their usual size within several days to weeks after the body fights off the infection.

However, sometimes swollen glands can be a sign of health conditions that require medical attention. A person should contact a doctor if swollen lymph nodes:

  • continue growing
  • are larger than 1 centimeter wide
  • do not start shrinking in a few weeks
  • feel more like marbles than tissue
  • are beneath inflamed skin
  • occur alongside the following symptoms:
  • are draining
  • develop in a person with no clear signs of illness or infection

The outlook is positive for people who develop swollen glands after receiving an mRNA COVID-19 vaccine. Most often, the swelling reduces significantly within 10 days after the vaccination.

If a person develops swollen lymph nodes due to COVID-19 infection, their outlook depends on:

  • their general health
  • other underlying conditions
  • the treatment they receive

Lymph node swelling due to common infections typically improves without medical treatment in roughly 2 weeks.

Swollen lymph glands are fairly common. Infections often cause this swelling, which tends to get better without medical treatment. A person should seek medical attention if they experience any other symptoms or notice the swelling does not improve.

There is also a possible link between swollen lymph nodes and COVID-19. A person may develop swollen lymph nodes after receiving an mRNA vaccine or as an unusual symptom of COVID-19 infection.

The swelling tends to reduce over time. A person can also try home remedies such as using a warm compress, taking pain reliever medications, and having plenty of fluids and rest.