TB skin test or TB blood test: which one do you need?
The clinic offers both kinds of TB test: the PPD skin test (also called the Mantoux or tuberculin skin test) and a TB blood test (T-Spot or TB Gold). If a school, employer or program sent you, check their form first, since many name the test they accept.
| PPD skin test | TB blood test | |
|---|---|---|
| Visits | Two: one to place it, one to read it | One blood draw |
| How it is done | A small amount of test fluid goes just under the skin of the inner forearm | A blood sample is drawn and tested in a lab |
| When you get a result | At the read, 48 to 72 hours after placement | CDC says often within 24 hours, sometimes several days, depending on the lab |
| If you had the BCG vaccine | BCG can cause a false positive | Not affected by BCG |
| Children under 5 | The test current CDC guidelines recommend | Some experts use it; your child's provider decides |
| Green card exam, age 2 and up | Not accepted | Required |
More answers
When do you come back to have a PPD skin test read?
CDC says the skin test must be read between 48 and 72 hours after it is placed. A test that is not read by the 72 hour mark cannot be read late; you start over with a new one.
At the read, a trained health care worker measures any firm swelling where the test went in, in millimeters; redness alone does not count. CDC sets the cutoff at 5, 10 or 15 millimeters depending on your risk, so the result is judged against your history, not one fixed number.
Plan the second trip before the first. The clinic is open every day, so a test placed on a Friday comes due on Sunday or Monday. Ask what time to return before you leave.
Who should get the TB blood test instead?
CDC prefers the blood test in two situations:
- You had the BCG vaccine. BCG is a TB vaccine that many people born outside the U.S. have had. It can make a skin test look positive when there is no infection, and it does not affect the blood test. CDC says that if you have ever had BCG, your provider should recommend the blood test.
- A second trip is hard. One blood draw removes the risk of a missed read.
Two timing points apply to both tests. CDC lists live vaccines, including measles, mumps, rubella, chickenpox (varicella) and yellow fever, as able to interfere with TB test results, so the TB test should be done the same day as that shot or at least one month after it. And if you were around someone with TB recently, say so: CDC notes a skin test can miss an infection picked up within the past 8 to 10 weeks.
Need a TB test for work, school or nursing school?
Many jobs, schools and health care training programs ask for a TB test before you start. Before you come:
- Bring the form or letter that lists the requirement, so the result is written up the way they want it.
- Check whether they want a skin test, a blood test, or either.
- If the form says "two-step," it means a second skin test 1 to 3 weeks after a negative first one, which CDC uses as a baseline for people who will be retested over time. That is four trips in all, unless the program accepts one blood test instead.
- Ask for a written copy of your result. CDC suggests keeping one because a positive result can stay positive on later tests, even after treatment.
For health care workers, CDC recommends TB screening at hire (a risk check, a symptom review and a TB blood or skin test) but not routine yearly testing unless there was a known exposure or ongoing spread at the facility. Your employer's policy still decides what you turn in. If the same job or program also wants a full exam, see school, sports and work physicals.
What TB test does a green card medical exam use?
For the I-693 immigration exam, CDC's technical instructions for civil surgeons call for a TB blood test for every applicant age 2 and older; a skin test is not accepted at those ages. A positive blood test means a chest x-ray is required. On its immigration price list, this clinic posts $150 for the T-Spot or TB Gold and $115 for that chest x-ray. Vaccines, the sealed envelope and the rest of the exam are covered on the immigration physical page.
What happens if your TB test is positive?
A positive skin or blood test usually means TB germs are in your body. On its own it does not tell you whether that is inactive TB or TB disease, so more tests follow, commonly a chest x-ray and sometimes a sputum (phlegm) test. The clinic has x-ray on site if your provider orders one.
Inactive TB (also called latent TB infection) causes no symptoms and cannot spread to other people, but it can turn into TB disease months or years later. If the tests point to inactive TB, your provider will talk with you about treatment. A negative result makes TB unlikely, though CDC says more testing may still be needed if you have symptoms, HIV, or a recent exposure.
Tell the provider about any cough, fever, chills, night sweats or weight loss. If you have trouble breathing or chest pain, call 911.
Who should get a flu shot this season?
CDC's advice is plain: everyone 6 months and older should get a flu vaccine every season, with rare exceptions. For the 2026 to 2027 season, CDC says every flu vaccine is trivalent, made to protect against two influenza A viruses and one influenza B virus.
It matters most for people more likely to get seriously sick from flu, including adults 65 and older, young children, people who are pregnant or gave birth within the past 2 weeks, nursing home residents, and people with asthma, diabetes, heart disease, kidney or liver disease, or a weakened immune system.
A few people should skip it or use a different vaccine:
- Babies younger than 6 months are too young for a flu shot.
- Anyone who had a severe allergic reaction to a past dose of a flu vaccine should not get that vaccine again.
- Anyone with a severe, life-threatening allergy to an ingredient other than egg proteins should avoid that vaccine.
Egg allergy alone is not a reason to skip. CDC says people with an egg allergy can get any flu vaccine that otherwise fits their age and health, and extra safety steps are no longer recommended.
Is it too late to get a flu shot?
CDC calls September and October good months to get vaccinated and aims for everyone to be done by the end of October. Missing that target is not a reason to skip: CDC says to keep getting vaccinated as long as flu viruses are a threat in your community. Protection takes about two weeks to build after the shot, so sooner is better.
Some children need two doses, given at least four weeks apart. The provider will tell you if your child does.
A sore, red or swollen arm, headache, fever, nausea, muscle aches or tiredness can follow the shot, and these are usually mild and short-lived. You can walk in for a flu shot without booking ahead.
How much does a TB test or flu shot cost?
| Service | Price |
|---|---|
| PPD skin test | Call for current price |
| TB blood test for work, school or your own records | Call for current price |
| TB blood test (T-Spot or TB Gold) as part of an immigration exam | $150 posted |
| Chest x-ray after a positive immigration TB blood test | $115 posted |
| Flu shot | Call for current price |
Both posted prices come from the clinic's immigration price list. Call (714) 400-2959 to confirm them and to ask about TB and flu prices outside an immigration exam. If you have insurance, check your plan's coverage for vaccines and lab tests; if you are paying yourself, see self-pay visits.
Walk in for a flu shot or save your spot online. For a TB test, call ahead to confirm timing or save a lab work spot.
Common questions
Can I get a flu shot and a TB test at the same visit?
Is QuantiFERON the same as T-Spot?
Do I need a TB test every year for work?
Does the flu shot give you the flu?
Where can I get a TB test near me in Anaheim?
Sources
- CDC: Testing for Tuberculosis
- CDC: Testing for Tuberculosis, Skin Test
- CDC: Testing for Tuberculosis, Blood Test
- CDC: Clinical Testing and Diagnosis for Tuberculosis
- CDC: Clinical Testing Guidance for Tuberculosis, Tuberculin Skin Test
- CDC: Clinical Testing Guidance for Tuberculosis, Interferon Gamma Release Assay
- CDC: TB Screening and Testing of Health Care Personnel
- CDC: Technical Instructions for Civil Surgeons, Tuberculosis
- CDC: Key Facts About Seasonal Flu Vaccine
- CDC: Who Needs a Flu Vaccine
- CDC: Preventing Seasonal Flu
- CDC: People at Increased Risk for Flu Complications
Updated October 29, 2026