Meningitis is an inflammation of the membranes surrounding your brain and spinal cord. Most cases of meningitis are caused by a viral infection, but bacterial and fungal infections also can lead to meningitis. Depending on the cause of the infection, meningitis can get better on its own in a couple of weeks, or it can be a life-threatening emergency requiring urgent antibiotic treatment.
Meningitis usually results from a viral infection, but the cause may also be a bacterial infection. Less commonly, a fungal infection may cause meningitis.
Acute bacterial meningitis usually occurs when bacteria enter the bloodstream and migrate to the brain and spinal cord. But it can also occur when bacteria directly invade the meninges, as a result of an ear or sinus infection, or a skull fracture, or rarely, after some surgeries.
Each year, viruses cause a greater number of cases of meningitis than do bacteria. Viral meningitis is usually mild and often clears on its own. These viruses tend to circulate in late summer and early autumn. Viruses such as herpes simplex virus, HIV, mumps and others also can cause viral meningitis.
Chronic forms of meningitis occur when slow-growing organisms invade the membranes and fluid surrounding your brain. Although acute meningitis strikes suddenly, chronic meningitis develops over two weeks or more.
Fungal meningitis is relatively uncommon and causes chronic meningitis. Occasionally it can mimic acute bacterial meningitis. However, this form of meningitis isn't contagious from person to person
It's easy to mistake the early signs and symptoms of meningitis for the flu. Meningitis signs and symptoms may develop over several hours or over one or two days.
The signs and symptoms that may occur include:
- Sudden high fever
- Severe headache that isn't easily confused with other types of headache
- Stiff neck
- Vomiting or nausea with headache
- Confusion or difficulty concentrating
- Sleepiness or difficulty waking up
- Sensitivity to light
- Lack of interest in drinking and eating
- Skin rash
Viral meningitis may improve without treatment, but bacterial meningitis is serious, can come on very quickly and requires prompt antibiotic treatment to improve the chances of a recovery. Delaying treatment for bacterial meningitis increases the risk of permanent brain damage or death. In addition, bacterial meningitis can prove fatal in a matter of days.
The complications of meningitis can be severe. The longer you or your child has the disease without treatment, the greater the risk of seizures and permanent neurological damage, including:
- Hearing loss
- Memory difficulty
- Learning disabilities
- Brain damage
- Gait problems
- Kidney failure
The treatment depends on the type of meningitis you or your child has.
Acute bacterial meningitis requires prompt treatment with intravenous antibiotics and, more recently, cortisone medications, to ensure recovery and reduce the risk of complications, such as brain swelling and seizures.
Antibiotics can't cure viral meningitis, and most cases improve on their own in several weeks. Treatment of mild cases of viral meningitis usually includes:
- Bed rest
- Plenty of fluids
- Over-the-counter pain medications to help reduce fever and relieve body aches
Meningitis typically results from contagious infections. Common bacteria or viruses that can cause meningitis can spread through coughing, sneezing, kissing, or sharing eating utensils, a toothbrush or a cigarette. You're also at increased risk if you live or work with someone who has the disease.