What causes herpes encephalitis?

Herpes encephalitis is caused by herpes simplex virus type 1 (HSV-1), the same virus responsible for cold sores around the mouth. In rare cases, HSV-1 travels from nerve pathways to brain tissue, triggering severe inflammation and swelling. This occurs either during a primary HSV-1 infection or when a dormant virus reactivates, though the exact trigger for brain involvement remains unclear in most cases.

What is the best test for herpes encephalitis?

The Herpes Simplex Virus 1 and 2 (IgG), Type Specific Antibodies test is the most important blood test for herpes encephalitis because it detects IgG antibodies indicating past or current HSV-1 exposure. While cerebrospinal fluid (CSF) analysis remains the primary diagnostic method, this blood test provides essential supporting evidence by confirming your immune system has encountered HSV-1. High antibody levels combined with symptoms like severe headache, fever, confusion, or seizures help doctors connect the infection to brain involvement and guide urgent treatment decisions.

When should I get tested for herpes encephalitis?

You should get tested immediately if you experience sudden severe headache, high fever, confusion, personality changes, seizures, or difficulty speaking. Anyone with a history of cold sores who develops neurological symptoms needs urgent evaluation. Herpes encephalitis is a medical emergency requiring immediate professional care, as early antiviral treatment significantly improves outcomes and can prevent permanent brain damage or death.

What are the symptoms of herpes encephalitis?

Symptoms of herpes encephalitis develop suddenly and include severe headache, high fever (often above 101°F), confusion, personality changes, and seizures. You might also notice difficulty speaking, memory problems, hallucinations, weakness on one side of the body, or unusual drowsiness. Some people experience sensitivity to light, stiff neck, or loss of consciousness. These symptoms indicate brain inflammation and require immediate emergency medical attention.

Who is at risk for herpes encephalitis?

Anyone can develop herpes encephalitis, but certain groups face higher risk. People with weakened immune systems from HIV, cancer treatment, or immunosuppressive medications are more vulnerable. Newborns and infants have increased susceptibility due to developing immune systems. Adults over 50 and anyone with a history of HSV-1 infections (cold sores) also carry elevated risk, though most people with cold sores never develop brain complications.

What happens if herpes encephalitis is left untreated?

Untreated herpes encephalitis causes permanent brain damage in most cases and has a death rate exceeding 70 percent. Survivors often experience severe long-term complications including memory loss, personality changes, speech difficulties, seizure disorders, and paralysis. The virus destroys brain tissue rapidly, particularly in areas controlling memory and emotion. Even with treatment, approximately one-third of patients experience lasting neurological problems, making immediate medical intervention absolutely critical for survival and recovery.

Can herpes encephalitis be diagnosed with a blood test?

Blood tests cannot definitively diagnose herpes encephalitis alone but play an important supporting role. The HSV antibody blood test detects your immune response to HSV-1, confirming viral exposure that helps doctors piece together the diagnostic puzzle. Doctors primarily rely on cerebrospinal fluid analysis through spinal tap to detect viral DNA in the fluid surrounding your brain and spinal cord. Brain imaging like MRI and clinical symptoms complete the diagnostic picture alongside blood test results.

How is herpes encephalitis treated?

Herpes encephalitis requires immediate hospitalization and intravenous antiviral medication, typically acyclovir, administered for 14 to 21 days. Treatment must begin within hours of symptom onset to prevent permanent brain damage. Doctors may also prescribe anti-seizure medications, corticosteroids to reduce brain swelling, and supportive care including fluids and fever management. After hospital discharge, many patients need long-term rehabilitation including physical therapy, speech therapy, and occupational therapy to recover lost functions.

How can I prevent herpes encephalitis?

You cannot completely prevent herpes encephalitis if you carry HSV-1, but managing cold sore outbreaks reduces reactivation risk. Avoid touching cold sores and wash hands frequently to prevent viral spread. People with weakened immune systems should discuss preventive antiviral medication with their doctor. Maintain a strong immune system through adequate sleep, stress management, and healthy nutrition. If you experience cold sore outbreaks with unusual neurological symptoms like confusion or severe headache, seek immediate medical evaluation.

What can I do at home for herpes encephalitis?

Herpes encephalitis is a medical emergency that cannot be managed at home and requires immediate hospitalization. Never attempt home treatment if you suspect brain infection. After hospital discharge and medical clearance, support recovery by taking all prescribed medications exactly as directed, attending all follow-up appointments, and participating in recommended rehabilitation therapies. Get plenty of rest, stay hydrated, and create a calm environment. Family members should monitor for any recurring symptoms like fever, confusion, or seizures and seek immediate medical attention if these develop.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

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Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

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Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

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Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

Herpes Encephalitis Blood Test

What is Herpes Encephalitis?

Herpes encephalitis is a rare but life-threatening viral infection of the brain tissue. It is caused by herpes simplex virus type 1 (HSV-1), the same virus that causes cold sores. The Herpes Simplex Virus 1 and 2 (IgG), Type Specific Antibodies test is the most important blood test for detecting HSV-1 antibodies that indicate viral exposure.

Written by Private MD Labs Medical Team

Last updated: December 29, 2025

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

support@privatemdlabs.com