Flu and Chronic Kidney Disease (CKD)

The flu is a respiratory illness caused by the influenza virus. It can be serious, especially for people with kidney disease. A yearly flu vaccine is the best prevention.

Table of Contents

About the Flu

The flu, or influenza, is a respiratory illness, meaning it affects lungs, airways and breathing. It is caused by the influenza virus. Flu illness can be mild for some people and severe for others. People with kidney disease have a higher risk for more severe illness.

Flu and CKD

People living with chronic kidney disease (CKD) have a higher risk of developing serious flu illness. CKD weakens the immune system, making it harder to fight off infections like flu. 

People living with a kidney transplant receiving immunosuppressants (anti-rejection medicines) are at higher risk of severe flu illness. Immunosuppressants are important medicines to help preserve a kidney transplant. They work by calming the immune system, which can increase the risk of infection. Some people with a glomerular disease treated with long-term prednisone (or other steroids) or another immunosuppressant can also be at higher risk of flu illness.

Signs and Symptoms

Flu symptoms can often seem to come on suddenly. Symptoms can appear anywhere 1 to 7 days after being exposed and infected. However, most of the time, symptoms appear within 2 to 3 days. Symptoms usually last 5 to 7 days. Symptoms can include:

  • Fever
  • Chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue (tiredness)

Causes

The flu is caused by the influenza virus. It can spread from person to person. The influenza viruses spread mainly by tiny droplets made when a person with the flu coughs, sneezes, or talks. It can also spread by touching a contaminated surface and then touching your mouth, nose, or eyes. However, most people get the flu by breathing in tiny droplets that enter the air by a person with the flu.

Types

The main known types of influenza viruses include types A, B, C, and D. Influenza A and B viruses typically cause seasonal epidemics (country or regional spread) of disease in people (known as flu season) almost every winter in the United States.

Influenza A viruses can cause pandemics, which is a widespread global epidemic spread of disease. 

You may have heard of types such as H1N1. This refers to subtypes of influenza A viruses. Types can be divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N). Influenza A subtypes that commonly spread among people during flu season include A(H1N1) and A(H3N2).

The bird (avian) flu is different from seasonal flu. It infects and spreads among birds in the wild. There have been outbreaks in poultry and dairy farms. In rare cases, people have gotten the bird flu from an infected animal - usually poultry or dairy workers in close contact with an infected animal.

Complications

Severe flu illness can lead to serious complications, including the following:

  • Pneumonia
  • Bronchitis
  • Inflammation of the heart (myocarditis), brain (encephalitis), or muscles (myositis)
  • Ear or sinus infections

The flu can also worsen chronic medical conditions, such as heart failure or asthma.

More severe and life-threatening complications can include sepsis and organ failure.

Diagnosis

A healthcare professional will perform a physical exam and will check for signs and symptoms. However, symptoms can resemble other illnesses, so flu tests will be done to confirm the flu. Flu tests are usually done with a nasal swab from the nose or back of the throat, while some may use saliva.

Tests

Common lab tests include the following:

Rapid antigen tests

These tests can give results in about 15 to 30 minutes. They can be done in the exam room. They detect flu virus antigens. An antigen is a foreign substance that causes an immune response in the body.

RT-PCR tests

RT-PCR (reverse transcription polymerase chain reaction) tests are more accurate than rapid tests. It can take 1 to 2 days for a result. Samples are usually sent to a lab. RT-PCR tests detect the virus's genetic material. These tests are also used to find out the type and subtype of a virus.

Other tests

In severe cases, a doctor may order a chest X-ray or CT scan if a bacterial co-infection or pneumonia is suspected. 

Prevention

Prevention methods include getting an annual flu vaccine (shot), frequent handwashing, and covering coughs and sneezes.

The best way to prevent the flu is to get a yearly flu vaccine.

 

A flu vaccine can help your body fight off diseases like the flu. Getting a flu vaccine can keep you from getting very sick if you do catch the flu.

The flu vaccine is updated every year to protect against the flu strains that are spreading the most each winter.

The injectable flu vaccine contains inactive flu viruses that produces an immune response, but are not infectious. The injectable influenza vaccines are recommended for everyone over age 6 months, but especially for people with CKD and other health conditions. This type of flu vaccine has a long, established safety record in people with CKD. These flu vaccines come in a standard or higher dose. People with kidney disease may get the higher dose vaccine, although it is currently only approved by the FDA for people over the age of 65.

The nasal spray flu vaccine contains live, weakened flu viruses that produce an immune response without causing infection. However, they should be avoided by people with CKD if possible and completely avoided by people with a kidney transplant or anyone taking long-term prednisone or other steroid, or any immunosuppressant (anti-rejection medicine).

Speak with a healthcare professional to find out which flu vaccine is right for you.

Flu Vaccine Recommendations (CDC)
Everyone with CKD or on dialysis
  • 1 flu vaccination every year
  • Avoid the live (nasal) version of this vaccine if possible
People with weakened immune system or immunosuppressed (for example, living with a kidney transplant)
  • 1 flu vaccination every year
  • Do not use the nasal spray (live vaccine). It is not safe for people with very weak immune systems.
Visit the CDC website for more information on the seasonal flu (influenza) vaccine

Having the flu (influenza) can raise the risk of getting pneumococcal disease. Therefore, protection against pneumococcal disease is especially important during flu season. You should make sure you’re updated with both types of vaccines. 

Other ways to reduce the risk of getting the flu can include:

  • Wash hands regularly
  • Cover your coughs and sneezes
  • Avoid close contact with sick people
  • Avoid touching your eyes, nose, and mouth

Treatment

Overview

Flu recovery can include home care or medications.

Rest

If you have the flu, you should get plenty of rest. Your body needs sleep to help your immune system fight the infection. 

Hydrate

Drink plenty of fluids like water to prevent dehydration. Ask a healthcare professional about the right amount of fluid for you. For example, people with dialysis may need to limit the amount of fluid they can drink to prevent fluid overload.

Pain Medicines

People with CKD can use acetaminophen to manage fever, headache, or body aches. NSAIDs such as ibuprofen should be avoided if you have kidney disease. Avoid aspirin to children or teenagers, as it can cause a rare but fatal condition called Reye's syndrome.

Antiviral medicines

Antiviral medicines are prescription medications that can shorten the time of having the flu and lower the risk of complications. They work best if started within 48 hours of the start of symptoms. Antivirals for the flu include oseltamivir (Tamiflu), zanamivir (Relenza), peramivir (Rapivab), and baloxavir marboxil (Xofluza). Antivirals are not the same as antibiotics, which work against bacteria but do not work against viruses. A healthcare professional can determine if antiviral medication is right for you. If you have advanced CKD, the prescribed dose of your antiviral medicine may need to be lowered.

If you’re sick, you should avoid spreading the virus by staying home and away from others, except to seek medical care. You should stay home until at least 24 hours after your fever is gone.

Questions to ask

  • Am I up to date with my vaccines, including my flu vaccine?
  • When should I get a flu vaccine?
  • What should I do if I think I get the flu?
  • What should I do if someone I live with gets the flu?

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This content is provided for informational use only and is not intended as medical advice or as a substitute for the medical advice of a healthcare professional.
© 2026 National Kidney Foundation, Inc.