Aseptic meningitis is a type of meningitis caused by something other than bacteria, usually a virus. It causes the tissues covering your brain and spinal cord to become inflamed.

Aseptic meningitis is more common than bacterial meningitis, but its symptoms are usually less severe. As it is often caused by a virus, it is sometimes called viral meningitis.

Read on to learn more about aseptic meningitis, including symptoms and causes, how doctors diagnose the condition, treatment options, and more.

The symptoms of aseptic meningitis can differ for adults and children.

Adults are more likely to experience symptoms such as:

Children are more likely to experience:

Signs and symptoms of aseptic meningitis in babies up to the age of 3 months of age can include irritability and bulging on the soft part of the top of the head.

Factors that may also lead to testing for aseptic meningitis in newborn babies include:

  • premature birth
  • maternal illness
  • low hemoglobin levels of less than 10.7 milligrams (mg)/decilitre (dL)
  • elevated serum white blood cell count

Symptoms of aseptic meningitis typically last around 7 to 10 days, though they can last between 5 and 14 days for some people.

Viruses are the most common cause of meningitis.

Examples of viruses that can cause aseptic meningitis include:

You can contract viruses by coming into contact with the cough, saliva, or fecal matter of a person with the virus. You can also contract some of these viruses from a mosquito bite.

In rare cases, other conditions can lead to aseptic meningitis. Examples include:

Anyone can get aseptic meningitis, but the highest rates occur among children under age 5 years.

People are also more likely to develop meningitis if they:

  • have a condition that weakens their immune system
  • have a weakened immune system due to a recent organ or bone marrow transplant
  • receive certain medical treatments, such as chemotherapy

If your doctor suspects you have meningitis, they’ll order tests to determine whether you have aseptic meningitis or bacterial meningitis.

In most cases, your doctor will perform a lumbar puncture, or spinal tap. During this procedure, your doctor will extract cerebrospinal fluid from your spine.

Spinal fluid is made by the brain and surrounds the brain and spinal cord to protect it. Your spinal fluid will have high protein levels and an increased white blood cell count if you have meningitis. This fluid can also help your doctor determine whether bacteria, viruses, or other infectious agents are causing the meningitis.

Lumbar puncture is the only definitive way to diagnose meningitis. Your doctor may also order other tests to determine the virus that caused the aseptic meningitis. The tests can include blood tests or imaging tests, such as X-rays and CT scans.

Treatment options for aseptic meningitis may depend on the specific cause of the meningitis. Most people with aseptic meningitis recover in weeks or months without medical treatment.

Your doctor might also prescribe medications if the aseptic meningitis was caused by a fungal infection or by a treatable virus, such as herpes.

Resting, drinking plenty of water, and taking pain relief medications may help. Your doctor may also recommend anti-emetics to manage vomiting.

It’s best to contact a doctor if you suspect aseptic meningitis. Aseptic meningitis can also cause dangerous complications, such as seizures, so it’s important for your doctor to monitor your condition while you recover.

You should call your doctor as soon as possible if any of the following symptoms develop:

  • stiff, painful neck
  • debilitating, persistent headache
  • confusion
  • seizures

These may be symptoms of another, potentially more serious medical condition.

Very few people with aseptic meningitis end up with a lasting illness. The majority of cases resolve within weeks or months after the onset of symptoms.

In some cases, aseptic meningitis can lead to encephalitis, or inflammation of the brain.

It’s important to contact your doctor if you suspect aseptic meningitis. You should also let your doctor know if symptoms do not resolve after several months or with medical treatments.

It may not be possible to completely prevent aseptic meningitis. However, steps that may help reduce the risk include:

  • getting all vaccines your doctor recommends
  • regularly washing your hands
  • avoiding touching your mouth, eyes, or nose
  • staying at home if you are unwell
  • avoiding close contact with people who are unwell

Aseptic meningitis is a type of meningitis usually caused by viral infections, such as enteroviruses, varicella-zoster virus, herpes simplex, West Nile, and HIV.

Symptoms of aseptic meningitis in adults can include fever, nausea and vomiting, headaches, malaise, weakness, photophobia, and a stiff neck. Children may experience fever, irritability, a rash, respiratory problems, and a stiff neck. Newborns may have a premature birth and bulging on the top of the head.

Lumbar puncture can help confirm an aseptic meningitis diagnosis. Most cases resolve without medical treatment within weeks or months, but your doctor may recommend medications to treat the specific virus and ease symptoms.