What is CMV?
CMV stands for cytomegalovirus, a common virus in the herpes family. Most adults and children have been exposed to CMV at some point in their lives. In healthy individuals, the virus often produces no symptoms at all or causes only a mild illness similar to the common cold. However, for certain groups, including pregnant women and people with compromised immune systems, cytomegalovirus can lead to significant health complications. Among the more troubling consequences of CMV infection are dizziness and hearing loss, which can affect both children born with the virus and adults who develop a severe infection.
How CMV Spreads
Cytomegalovirus spreads through direct contact with bodily fluids, including saliva, urine, blood, tears, semen, and breast milk. It can also be transmitted from a mother to her unborn child across the placenta, which is how congenital CMV occurs. Because the virus can be shed for months after an infection, it is easily passed among young children in daycare settings and from children to adults. Once a person is infected with CMV, the virus remains in the body for life, usually in a dormant state. Reactivation can happen later, especially when the immune system becomes weakened.
Symptoms of CMV Infection
Most healthy people who catch cytomegalovirus never realise they have been infected. When symptoms do appear, they may include fever, sore throat, fatigue, swollen glands, and muscle aches. These signs are often mistaken for mononucleosis or influenza. In more serious infections, particularly in people with weakened immunity, CMV can affect the eyes, lungs, liver, oesophagus, and the digestive tract. Neurological symptoms are less common but can be serious; some patients report vertigo, unsteadiness, and dizziness, which may arise when the virus affects the inner ear, the vestibular nerve, or the central nervous system.
Congenital CMV and Its Long-Term Effects
Congenital CMV is the leading viral cause of birth defects in many developed countries. Around one in every two hundred newborns is born with cytomegalovirus. Most of these infants are asymptomatic at birth, but a significant number will later develop long-term health issues. The most common consequence of congenital CMV is sensorineural hearing loss, which may be present at birth or appear months or even years later. Children with congenital CMV may also experience vision problems, developmental delays, seizures, and balance disorders. Among the lesser-known but distressing symptoms is dizziness, which can emerge as a result of damage to the vestibular portion of the inner ear. Because hearing and balance share the same intricate structures of the inner ear, CMV-related damage often affects both functions simultaneously.
CMV and Hearing Loss
Hearing loss is one of the hallmark complications of cytomegalovirus infection, especially when the infection occurs before birth. The virus can damage the cochlea, the spiral-shaped organ in the inner ear that converts sound vibrations into nerve signals. This damage leads to sensorineural hearing loss, which is typically permanent. Hearing loss caused by CMV may be unilateral or bilateral, mild or profound. It can also be progressive, meaning that a child who passes newborn hearing screening may still lose hearing later in infancy or childhood. For this reason, children with congenital CMV are advised to undergo regular audiological evaluations, even if they hear well at first. In adults, CMV-associated hearing loss is more common in those with weakened immune systems, such as organ transplant recipients or people living with advanced HIV infection.
CMV and Dizziness
Dizziness is a symptom that is often overlooked in discussions about cytomegalovirus, yet it is a genuine and sometimes disabling complaint. CMV can affect the vestibular labyrinth, which is the part of the inner ear that governs balance. When the virus causes inflammation in this region, patients may experience vertigo, a spinning sensation, or persistent unsteadiness. Dizziness in CMV infection can also stem from viral involvement of the brainstem or the cerebellum, which help coordinate balance. Some patients describe a feeling of floating, swaying, or being unstable on their feet. In infants with congenital CMV, balance problems may not be recognised until the child begins to walk; parents might notice frequent falls, clumsiness, or a reluctance to move. Older children may complain of motion sickness or dizziness during car rides. Because dizziness can significantly reduce quality of life, it should be taken seriously in anyone with a history of CMV exposure.
Diagnosis of CMV
Diagnosing cytomegalovirus requires laboratory testing. In newborns, congenital CMV is confirmed by detecting the virus in saliva, urine, or blood within the first three weeks of life. Testing after that age cannot distinguish between congenital and postnatal infection. In older children and adults, a diagnosis of active CMV infection can be made using polymerase chain reaction tests, which detect the genetic material of the virus, or serology tests, which look for antibodies. When dizziness and hearing loss are present together, an ear, nose, and throat specialist may perform additional tests such as audiometry, vestibular testing, and imaging of the inner ear and brain to determine whether CMV is the underlying cause.
Treatment and Management
There is no cure for CMV, and treatment is not usually required for healthy individuals with mild symptoms. Antiviral medications such as ganciclovir, valganciclovir, foscarnet, and cidofovir can help control the virus in severe cases, particularly in people with weakened immune systems and in infants with congenital CMV affecting the internal organs. Early treatment with antivirals may also slow the progression of hearing loss in some newborns. For dizziness, management may include vestibular rehabilitation therapy, which trains the brain to compensate for inner ear deficits, as well as medications that reduce vertigo. Hearing loss is addressed with hearing aids or cochlear implants, depending on its severity. Children with congenital CMV should receive coordinated care from audiologists, developmental paediatricians, neurologists, and vestibular therapists to ensure the best possible outcome.
Preventing CMV Infection
Prevention of cytomegalovirus focuses on hygiene and, for pregnant women, avoiding exposure to the bodily fluids of young children. Hand washing with soap and water is highly effective, especially after changing nappies, feeding a child, or wiping a child's nose. Avoiding sharing food, drinks, cutlery, or toothbrushes with young children, and not kissing children on the lips, can reduce the risk of transmission. Pregnant women who work in childcare or healthcare settings should be especially careful. There is currently no vaccine for CMV, although research efforts are ongoing. Screening newborns for congenital CMV is not yet universal, but some regions have introduced targeted screening for babies who fail their hearing test, as early detection allows timely intervention.
When to Seek Medical Advice
Anyone who notices dizziness, hearing loss, or a combination of both should seek medical evaluation. This is especially important for infants and young children, as early diagnosis of CMV-related hearing and balance problems can lead to better developmental outcomes. Pregnant women who develop flu-like illness or who have been exposed to a child with confirmed CMV should discuss testing with their obstetrician. Adults with weakened immune systems who experience new dizziness or a sudden change in hearing should be evaluated promptly, as CMV can cause rapidly progressive disease in this population. Although CMV is common, the complications of dizziness and hearing loss deserve careful attention.