There are five types of meningitis, each caused by different factors. The two most common forms of the disease are viral meningitis and bacterial meningitis. Viral meningitis often resolves on its own without treatment. But if you have bacterial meningitis, early diagnosis and treatment is vital. If treatment is delayed because symptoms are mistaken for the flu, there can be devastating consequences. Symptoms such as sudden fever, severe headache, and a stiff neck are possible indications of meningitis. Anyone experiencing these symptoms should seek immediate medical attention — it’s definitely a case of better safe than sorry. “The onset may be very sudden, and the progression even faster,” says Malcolm Thaler, MD, an internist with One Medical Group in New York City. Making a Meningitis Diagnosis The first step of diagnosing meningitis is a physical exam, and there are specific indicators for which your doctor can check. Your doctor may look for Brudzinski’s sign, an indicator in which stiffness in your neck causes you to automatically flex your knees and hips when your doctor forces you to flex your neck. “The doctor may also look for Kernig’s sign,” says Dr. Thaler. This means you could feel severe pain in your thigh if you try to extend your leg, If meningitis is suspected, may start you on antibiotics right away, even before determining the type of meningitis you have. “Since the culture for virus and bacterial growth often takes a few days to come back, it would be very dangerous to wait for that information,” says Cathy Clements, MD, a primary care physician and internist at Mercy Medical Center in Baltimore. “That’s why the most important thing a doctor can do when a patient comes in with suspected meningitis is to go ahead and initiate treatment.” Antibiotics are prescribed based on the most common pathogens known to cause meningitis in certain age groups, Dr. Clements explains. Additional Diagnostic Tests for Meningitis When a meningitis diagnosis is suspected, there are several tests your doctor can run to confirm a diagnosis: Blood tests. Standard blood tests to analyze antibodies and foreign proteins can alert your doctor to the presence of infection. CT scan. A scan of the brain can reveal inflammation, internal bleeding, or other abnormalities. It can also detect conditions such as brain swelling, abscess, or hemorrhage, which could make a lumbar puncture unsafe. Lumbar puncture. The inflammation associated with meningitis is most often caused by an infection of the cerebral spinal fluid, which surrounds the brain and spinal cord. A lumbar puncture, also known as a spinal tap, enables your doctor to collect a sample of this cerebrospinal fluid from a small area in your lower back. This fluid is sent to the lab and analyzed to determine if there is an infection. “We look for white blood cells, blood, protein, and glucose,” Clements says. “The results of these tests — and their ratios to each other — can give us an idea if the meningitis is bacterial, viral, or fungal.” She explains that bacterial meningitis tends to have more neutrophils (a certain type of white blood cell) and lower glucose levels. Viral meningitis tends to have more lymphocytes (another type of white blood cell) and more protein. “We also send it for culture for viruses and bacteria growth, which often takes a few days to come back,” she says. Once all the results are in, the medical team should have the information needed for a more precise diagnosis and further treatment.