Cytomegalovirus (CMV): Symptoms, Causes, Transmission, Treatment and Outlook — What You Need to Know
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Quick answer
Cytomegalovirus (CMV) is a common herpesvirus (HHV-5) that infects almost everyone at some point, usually without symptoms. It spreads through body fluids — saliva, urine, blood, breast milk, and semen — and stays dormant in your body for life. Most people never need treatment, but it can cause serious complications in people with weakened immune systems (especially transplant recipients) and can cause congenital CMV with hearing loss, vision loss, or developmental delays if a pregnant person is infected.
TL;DR
CMV is a widespread, mostly silent infection. Symptoms, when they occur, include fatigue, muscle aches, sweating, headache, sore throat, swollen lymph nodes, and rash. About 1 in 200 babies is born with CMV each year, and serious complications mainly affect immunocompromised people, who are treated with antiviral drugs such as ganciclovir or valganciclovir. Hygiene habits — handwashing and not sharing food or utensils — reduce the risk of transmission.
Limitation statement: the only statistics in the underlying clinical source are that about 1 in 200 babies is born with CMV each year, about 1 in 10 of those have symptoms at birth, and about 1 in 3 people are infected by age 5. No other statistics are presented in this article.
What is cytomegalovirus?
Cytomegalovirus (CMV) is a type of herpes virus that can sometimes make you sick. Almost everyone gets it at some point in their lives, but most people have mild or no symptoms.
CMV can cause serious complications if you have a weakened immune system. Organ and stem cell transplant recipients are at an especially high risk.
If you're pregnant and have CMV, your baby can be born with congenital CMV. Congenital CMV can cause vision or hearing loss and developmental delays. About 1 in 200 babies is born with CMV each year. About 1 in 10 have symptoms at birth.
What are the symptoms of cytomegalovirus?
Most people don't have symptoms of CMV. If you do, they could include:
Symptom | Description |
Extreme tiredness (fatigue) | Feeling run down, weak, or tired |
Muscle aches | Body aches |
Sweating | Including night sweats |
Headache | Common with symptomatic infection |
Sore throat | Throat irritation |
Glands enlarged | |
Rash | Skin rash |
Because these symptoms resemble common mild illnesses, most CMV infections go unnoticed. Symptoms can last anywhere from a week to several months, and you may feel run down, tired, or weak for several weeks or months.
What causes cytomegalovirus?
A type of herpes virus, human herpesvirus-5 (HHV-5), causes CMV infections.
If you've had CMV in the past, the virus can stay in your body, inactive. When your immune system is weakened, it can reactivate and cause you to get sick. While most people can fight off CMV without symptoms, a new or reactivated infection can cause serious complications in someone with a weakened immune system.
How does CMV spread?
You get CMV from the body fluids of someone else who's infected. This includes spit (saliva), pee (urine), blood, breast milk, and semen. It can spread through:
Transmission route | How it happens |
Direct contact with pee and spit | Especially from young children |
Sex | Through semen and other fluids |
Vertical transmission | From a pregnant person to the fetus |
Breastfeeding | Through breast milk |
Blood transfusion or organ transplant | Medical transmission routes |
Who is at higher risk?
You're at higher risk for cytomegalovirus if you have received an organ or stem cell transplant, are under the age of 5 (about 1 in 3 people get infected by age 5), work with or live with children under the age of 5, have a compromised immune system, or live in close contact with many other people.
What are the complications of cytomegalovirus?
Serious complications from CMV are rare. You're most likely to experience life-threatening health issues if you have a weakened immune system, especially if you've received an organ or stem cell transplant.
Complication | What it involves |
Encephalitis | Brain swelling |
CMV retinitis | Eye damage |
Gastritis or colitis | Inflammation in the digestive tract |
Lung inflammation and infection | |
Lasting cognitive issues | Trouble focusing, remembering, and problem-solving |
Donor organ rejection | Threatens the transplanted organ |
Tear or hole in esophagus or intestines | Severe digestive damage |
Recurrent fevers and tiredness | Ongoing systemic symptoms |
Miscarriage or stillbirth | Pregnancy loss |
Babies born with CMV can have lasting health conditions, including hearing or vision loss and developmental differences. Hearing loss can develop later, even if your child didn't have symptoms of CMV at birth. Infants with severe symptoms may have life-threatening complications of CMV.
How is cytomegalovirus diagnosed?
Healthcare providers use blood, urine, or saliva tests to diagnose CMV. As it usually causes mild symptoms, most people won't need to be tested.
Your healthcare provider may test you for CMV if you have a weakened immune system. Your child's healthcare provider may test them in their first few weeks of life if they have symptoms of congenital CMV.
How is cytomegalovirus treated?
Healthcare providers treat CMV with the antiviral medications ganciclovir (GCV) or valganciclovir (VGV). But you usually only need treatment if you have a compromised immune system. Providers also treat babies born with symptoms of CMV.
Antiviral medications can lessen the risk of health problems in babies born with CMV, but they may not completely prevent them. Speech and occupational therapy can help manage the effects of hearing loss and developmental issues in congenital CMV.
Can you prevent cytomegalovirus?
You can reduce your risk of CMV by avoiding contact with other people's body fluids.
Prevention step | How it helps |
Don't share food, cups, or eating utensils | Limits saliva contact |
Don't put a child's pacifier in your mouth | Limits saliva contact with young children |
Wash hands after bathroom, diaper changes, or helping a child | Soap and warm water after urine or saliva contact |
Use a condom during oral, anal, or vaginal sex | Limits fluid transmission, even with the same partner |
If you've received an organ transplant, your provider may treat you with antiviral medications to prevent CMV. They may monitor your blood so they can treat you as soon as possible if you do get an infection.
When should I see my healthcare provider?
Contact your provider right away if you have symptoms of CMV and have a weakened immune system, or if you think your baby has symptoms of congenital CMV.
Talk to your healthcare provider about steps you can take to prevent CMV if you have a compromised immune system, have or will have a stem cell or organ transplant, or are pregnant or plan to become pregnant.
A note from the clinical source: "Most of the time, CMV (cytomegalovirus) infections don't cause symptoms or complications. It's possible to go your whole life without having to think about it. But if you're pregnant or have a weakened immune system, take special care to avoid infection. Talk to your healthcare provider about how to reduce your risk of CMV based on your specific circumstances."
What can I expect if I have CMV?
What to expect depends on many factors. Your provider can help you know what to expect in your specific situation.
Most people don't have symptoms of CMV. If you do, you may need to rest and take breaks more often than you usually would, and symptoms can last anywhere from a week to several months. If you have a weakened immune system, you'll likely need to be hospitalized for treatment and monitoring. Early treatment gives you the best chance of a full recovery.
If your child was diagnosed with CMV at birth, you'll work closely with their care team to try to reduce the risk of lasting health effects. Some conditions, like hearing loss, can develop later in childhood.
How long does it take for CMV to go away?
Symptoms of CMV can last for a long time — you may feel run down, tired, or weak for several weeks or months. Once infected, CMV can stay in your body, inactive, for the rest of your life. If you have a weakened immune system, it can reactivate and cause serious symptoms or organ damage.
Conclusion: A mostly silent virus that demands attention for the vulnerable
Cytomegalovirus is one of the most common viruses on the planet — almost everyone carries it, and most people never know. For the average healthy person, CMV is a mild or symptom-free experience that resolves without treatment.
The picture changes for two groups. Pregnant people can pass CMV to their babies, where it may cause hearing loss, vision loss, and developmental delays — with hearing loss sometimes appearing later in childhood even when a newborn seems healthy. People with weakened immune systems, especially organ and stem cell transplant recipients, face the risk of severe, sometimes life-threatening complications if the dormant virus reactivates.
Simple hygiene habits meaningfully reduce transmission risk, and effective antiviral treatments exist for those who need them. Early testing and early treatment give the best chance of full recovery.
Your next step: If you are pregnant, planning a pregnancy, immunocompromised, or awaiting or recovering from a transplant, talk with your healthcare provider about your CMV risk and the specific prevention steps that apply to you. If you have CMV symptoms and a weakened immune system, contact your provider right away.
Frequently asked questions (FAQ)
What is cytomegalovirus? Cytomegalovirus (CMV) is a type of herpes virus (human herpesvirus-5, or HHV-5) that can sometimes make you sick. Almost everyone gets it at some point in their lives, but most people have mild or no symptoms.
Is CMV a type of herpes virus? Yes. CMV is caused by human herpesvirus-5 (HHV-5), one of the herpesviruses. Like other herpesviruses, it stays in your body for life.
Is cytomegalovirus contagious? Yes. It spreads through the body fluids of an infected person — saliva, urine, blood, breast milk, and semen — and through sex, vertical transmission during pregnancy, breastfeeding, and blood transfusion or organ transplant.
How do you get CMV? You get CMV from contact with an infected person's body fluids, including direct contact with saliva and urine, sexual contact, transmission from a pregnant person to the fetus, breastfeeding, and blood transfusion or organ transplant.
What are the symptoms of CMV in adults? Most people have no symptoms. When symptoms occur, they include extreme tiredness, muscle aches, sweating, headache, sore throat, swollen lymph nodes, and rash.
How long do CMV symptoms last? Symptoms can last anywhere from a week to several months. You may feel run down, tired, or weak for several weeks or months.
Can CMV stay in your body forever? Yes. Once infected, CMV can stay in your body, inactive, for the rest of your life. If your immune system weakens, it can reactivate and cause serious symptoms or organ damage.
What is congenital CMV? Congenital CMV is when a baby is born with CMV after the pregnant person was infected. It can cause vision or hearing loss and developmental delays. About 1 in 200 babies is born with CMV each year, and about 1 in 10 of those have symptoms at birth.
Can a baby get CMV from breast milk? Yes — CMV can spread through breast milk. Discuss risks and guidance with your healthcare provider, especially if your baby was born prematurely or has a weakened immune system.
What happens if you get CMV while pregnant? Your baby can be born with congenital CMV, which can cause hearing loss, vision loss, and developmental delays. Hearing loss can develop later in childhood even if the baby had no symptoms at birth.
Who is at highest risk for CMV complications? People with weakened immune systems — especially organ and stem cell transplant recipients — are at especially high risk for serious, sometimes life-threatening complications.
Why are children under 5 at risk for CMV? About 1 in 3 people get infected by age 5, and the virus spreads easily through contact with the saliva and urine of young children. People who work with or live with children under 5 have higher risk.
What are the serious complications of CMV? Complications can include encephalitis (brain swelling), CMV retinitis (eye damage), gastritis or colitis, pneumonitis and pneumonia, lasting cognitive issues, miscarriage or stillbirth, donor organ rejection, and tears or holes in the esophagus or intestines.
Can CMV cause hearing loss in children? Yes. Babies born with CMV can have lasting hearing loss, which can develop later in childhood even if they had no symptoms of CMV at birth.
How is CMV diagnosed? Providers use blood, urine, or saliva tests. Most people don't need testing since the infection is usually mild. Testing is considered for people with weakened immune systems and newborns with possible congenital CMV symptoms.
How is cytomegalovirus treated? With antiviral medications — ganciclovir (GCV) or valganciclovir (VGV). Treatment is usually needed only if you have a compromised immune system. Babies born with symptoms of CMV are also treated.
Does treatment fully prevent problems in congenital CMV? No. Antiviral medications can lessen the risk of health problems in babies born with CMV, but they may not completely prevent them.
How are the effects of congenital CMV managed? Speech and occupational therapy can help manage the effects of hearing loss and developmental issues. The child's care team works to reduce the risk of lasting health effects.
What happens if a transplant recipient gets CMV? They're at especially high risk for serious complications, including organ rejection, and will likely need to be hospitalized for treatment and monitoring. Antiviral drugs can be used both to treat and to prevent CMV in transplant patients.
Can CMV be prevented? You can reduce risk by avoiding contact with others' body fluids: don't share food, cups, or utensils; don't put a child's pacifier in your mouth; wash hands after diaper changes and bathroom use; and use condoms during sex.
Should I worry about CMV if I'm healthy? Most of the time CMV doesn't cause symptoms or complications, and it's possible to go your whole life without thinking about it. But if you're pregnant or have a weakened immune system, take special care to avoid infection.
When should I contact my healthcare provider about CMV? Contact your provider right away if you have CMV symptoms and a weakened immune system, or if you think your baby has symptoms of congenital CMV. Talk to your provider about prevention if you are immunocompromised, have or will have a transplant, or are pregnant or planning pregnancy.
Can CMV cause pneumonia? Yes. Pneumonia and pneumonitis (lung inflammation) are among the serious complications of CMV, especially in people with weakened immune systems.
Can CMV reactivate years later? Yes. The virus stays in your body inactive after infection, and a weakened immune system can trigger reactivation, which can cause serious symptoms or organ damage.
Is CMV an emergency for healthy people? Usually not — most people never notice they have it. The urgent situations involve weakened immune systems and babies with possible congenital CMV, who should be evaluated right away.
External references
Cleveland Clinic — Cytomegalovirus (CMV) (primary source, medically reviewed, last updated Jun 9, 2026)
HIV.gov — CMV: Guidelines for the Prevention and Treatment of Opportunistic Infections
Disclaimer: This article is for general educational purposes only and does not constitute medical advice. It is based on a single referenced clinical source and should not replace professional diagnosis or treatment. If you have CMV symptoms and a weakened immune system, or suspect your baby has congenital CMV, contact your healthcare provider right away.
Comments