Viral Infection Blood Test

What is Viral Infection?

Viral infections are illnesses caused by viruses that invade healthy cells and use them to reproduce. They are caused by various viruses including influenza, rhinovirus, coronavirus, and other viral pathogens that disrupt normal cellular function. The White Blood Cell Count (WBC) test is the most important test for assessing your immune response to viral infections.

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What causes viral infections?

Viral infections are caused by microscopic organisms called viruses that invade your body's cells and hijack them to reproduce. Common culprits include influenza viruses, rhinoviruses (which cause colds), coronaviruses, adenoviruses, and respiratory syncytial virus (RSV). These viruses spread through respiratory droplets when infected people cough or sneeze, through direct contact with contaminated surfaces, or through body fluids. Once inside your body, viruses attach to specific cells, inject their genetic material, and force your cells to create more virus particles, which then spread to infect additional cells throughout your body.

What is the best test for viral infections?

The White Blood Cell Count (WBC) test is the most important blood test for viral infections because it reveals how your immune system is responding to the viral invasion. During viral infections, your WBC count typically drops below normal levels (a condition called leukopenia) because many viruses suppress bone marrow function where white blood cells are produced. This distinctive pattern helps doctors distinguish viral infections from bacterial infections, which usually cause WBC counts to rise. A lower WBC count during illness strongly suggests a viral rather than bacterial cause, helping your healthcare provider avoid prescribing unnecessary antibiotics and focus on appropriate supportive care instead.

When should I get tested for a viral infection?

You should get tested if you experience persistent fever, extreme fatigue that interferes with daily activities, symptoms lasting longer than 7-10 days, or if you have underlying health conditions like diabetes, heart disease, or a weakened immune system that make you more vulnerable to complications. Testing is also important if you're unsure whether your illness is viral or bacterial, as this distinction determines whether antibiotics are needed. Get tested promptly if you develop difficulty breathing, chest pain, severe headache, or if your symptoms suddenly worsen after initially improving.

What are the symptoms of viral infections?
Viral infections typically cause fever or chills, persistent fatigue and body aches, sore throat and cough, runny or stuffy nose, and headaches. You might also experience digestive symptoms like nausea, vomiting, or diarrhea depending on the type of virus. Many people describe feeling generally unwell with muscle soreness throughout their body. Symptoms usually develop gradually over 1-3 days and can last anywhere from a few days to two weeks, though fatigue may persist longer.
Who is at risk for viral infections?
Anyone can get a viral infection, but certain groups face higher risks and more severe complications. Young children and older adults have weaker immune systems that struggle to fight off viruses effectively. People with chronic conditions like asthma, diabetes, heart disease, or immune system disorders are more vulnerable to serious complications. Healthcare workers and teachers have increased exposure to viruses through frequent contact with sick individuals. Living in crowded conditions, experiencing high stress levels, poor nutrition, and lack of adequate sleep all weaken your immune defenses and increase susceptibility to viral infections.
What happens if viral infections are left untreated?
Most viral infections resolve on their own with rest and supportive care, but leaving some untreated can lead to serious complications. Respiratory viruses like influenza can progress to pneumonia, bronchitis, or sinus infections that may require medical intervention. Some viruses can trigger secondary bacterial infections that do require antibiotics. In people with weakened immune systems or chronic health conditions, untreated viral infections can lead to hospitalization, organ damage, or life-threatening complications. Certain viruses like hepatitis or HIV cause chronic infections that damage organs over time if not properly managed with medical treatment.
Can viral infections be diagnosed with a blood test?
Blood tests cannot identify every specific virus, but they provide crucial information about how your body is responding to the infection. The White Blood Cell Count test is particularly valuable because it shows whether your immune system is reacting in a pattern typical of viral infections (usually a decreased WBC count) versus bacterial infections (usually an increased count). This distinction helps doctors make appropriate treatment decisions. For specific viruses like HIV, hepatitis, or Epstein-Barr virus, specialized antibody tests can directly detect the virus or your immune response to it, providing definitive diagnosis.
How are viral infections treated?
Most viral infections are treated with supportive care that helps your body fight off the virus naturally. This includes getting plenty of rest to allow your immune system to work effectively, staying well-hydrated with water and clear fluids, and taking over-the-counter medications like acetaminophen or ibuprofen to reduce fever and relieve aches. For certain serious viral infections like influenza, HIV, hepatitis, or COVID-19, antiviral medications can directly fight the virus and reduce symptom severity and duration. Antibiotics do not work against viruses and should only be used if a secondary bacterial infection develops.
How can I prevent viral infections?
Prevent viral infections by washing your hands frequently with soap and water for at least 20 seconds, especially before eating and after being in public spaces. Avoid touching your face, particularly your eyes, nose, and mouth, where viruses can easily enter your body. Stay up to date with recommended vaccinations including annual flu shots and COVID-19 vaccines. Maintain a healthy lifestyle with regular exercise, adequate sleep (7-9 hours nightly), and a balanced diet rich in fruits and vegetables to keep your immune system strong. Avoid close contact with people who are sick, and stay home when you're ill to prevent spreading viruses to others.
What natural remedies help with viral infections?
Natural remedies can support your recovery from viral infections alongside medical care. Stay well-hydrated by drinking warm liquids like herbal tea, broth, and warm water with honey and lemon, which soothe your throat and help thin mucus. Get plenty of quality sleep in a comfortable, cool room to allow your immune system to work efficiently. Gargle with warm salt water several times daily to relieve sore throat pain. Use a humidifier to add moisture to the air, which eases congestion and coughing. Consume vitamin C-rich foods like citrus fruits, and consider zinc supplements within the first 24 hours of symptoms, as some studies suggest they may shorten cold duration.
How’s this work?
Getting your blood test with us is easy, private & backed by the power of science.

Long story short:
  1. In the test options, use the filters or search box to narrow your choices and find the test you want.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!
  8. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.
How do I know which test to get?
In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option.

Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.
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?
Absolutely! We totally understand that errors can happen. No worries, we're here to help you.

Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you.

There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out.

Our lab requires an address to be listed to generate an order.
Do you accept health insurance?
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.
Can I cancel my order?
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.
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What this means

Your testosterone levels are slightly below the optimal range. While this is not necessarily cause for concern, it may contribute to occasional fatigue, reduced motivation, or lower muscle mass over time.

* Regular blood test results (e.g., CBC) typically start arriving the next business day after sample collection. More complex tests, such as hormone panels, may take up to 10–15 business days due to their complexity.

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* Regular blood test results (e.g., CBC) typically start arriving the next business day after sample collection. More complex tests, such as hormone panels, may take up to 10–15 business days due to their complexity.

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White Blood Cell Count (WBC)
What's included
Fast & easy, results by email & SMS
No need to visit a doctor
Private & confidential
No insurance needed
Results explained
No extra fees paid at the lab

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