What to Know About TB Symptoms
- Inactive (latent) TB has no symptoms
- Symptoms usually occur only with active TB disease
- TB tests can find infection before you feel sick
- Early diagnosis helps protect you and others
Symptoms of Tuberculosis
Symptoms of Active TB Disease
Symptoms depend on where in the body the TB germs are growing. TB germs that grow in the lungs can cause:
- A bad cough that lasts more than three weeks
- Chest pain
- Coughing up blood or mucus (sputum)
Other symptoms of active TB disease may include:
- Weakness or fatigue
- Loss of appetite
- Unintentional weight loss
- Fever
- Chills
- Night sweats
Inactive (Latent) TB
Inactive (latent) TB does not cause symptoms.
People with inactive TB:
- Do not feel sick
- Cannot spread TB to others
- May only know they have TB after a test
However, without treatment they can develop active TB disease and become sick. That's why TB testing is important if you believe you've been exposed.
When to Get Checked for TB
You should talk to a healthcare provider about TB testing if you:
- Have symptoms of active TB disease.
- Were exposed to someone who has active TB disease.
- Are at higher risk for developing active TB disease.
- Have health screening requirements for employment, school, travel or immigration.
Testing can help find TB early, even before symptoms begin.
How Tuberculosis Is Diagnosed
A healthcare provider will start by collecting a patient history to determine if you may have been exposed to TB. During a physical exam, they will use a stethoscope to listen to the lungs and check the lymph nodes in the neck for swelling.
There are two types of tests for TB infection:
TB Blood Test:
- Requires only one visit with a healthcare provider
- Uses a blood sample to find out of there is TB infection
- Measures how the immune system reacts to the germs that cause TB
TB Skin Test:
- Requires two visits with a healthcare provider
- Includes an injection of a small amount of fluid into the arm
- Measures the size of the bump or reaction from the injection (48-72 hours later)
What Do the Test Results Mean?
A positive test result for TB infection means there are TB germs in the body, but they do not show if TB is active. Your healthcare provider will do other tests to determine whether TB is active and if treatment is needed. These tests may include a chest X-ray and a test of the sputum (coughed-up mucus) for bacteria.
A negative test result for TB infection means inactive TB or active TB disease is unlikely, but your healthcare provider may do additional tests especially if:
What Happens After Diagnosis
If TB is diagnosed:
- Your healthcare provider will explain whether TB is inactive or active
- A treatment plan will be created
- Public health teams may help with care and follow‑up
TB is treatable and often curable, especially when diagnosed early.
Page last updated: March 20, 2026
