The main symptoms of tuberculosis depend on which form you have

Active tuberculosis usually starts with a cough that lasts more than three weeks. The cough is often dry at first, then produces mucus or sputum. You may also have chest pain when you breathe or cough, fever that comes and goes (often worse in the afternoon or evening), night sweats that soak your clothes and bedding, and unexplained weight loss or loss of appetite.

These symptoms develop slowly over weeks or months, not suddenly like flu. Many people ignore them at first because they feel mild, but the cough that does not go away is the signal to see a doctor. If you have been around someone with active TB, or if you have risk factors like HIV, diabetes, or a weakened immune system, mention that when you describe your symptoms.

Latent tuberculosis produces no symptoms at all. You carry the bacteria but your immune system keeps it contained. You will not cough, have fever, or feel sick. The only way to know you have latent TB is through a skin test or blood test, usually done after exposure or as part of a routine screening.

Key Takeaways

  • A cough lasting more than three weeks, especially one that produces mucus, is the most common sign of active tuberculosis and warrants a doctor visit.
  • Fever, night sweats, chest pain, weight loss, and loss of appetite often accompany the cough and develop gradually over weeks.
  • Latent tuberculosis causes no symptoms; you only learn you have it through testing after known exposure or during screening.
  • TB symptoms are easy to mistake for other illnesses, so tell your doctor if you have been near someone with active TB or have risk factors like HIV or diabetes.

When the cough is the main warning sign

The persistent cough is what brings most people to a doctor. It does not respond to over-the-counter cough medicine and does not clear up in a few weeks the way a cold or bronchitis usually does. After three weeks, a cough is no longer normal and needs investigation.

Early on, the cough may be dry. As the infection progresses, you start coughing up sputum—mucus that may be clear, white, or tinged with blood. Coughing up blood (hemoptysis) is less common but is a sign the infection has damaged lung tissue and needs urgent medical attention. Even without blood, any cough lasting more than three weeks should be evaluated.

Fever and night sweats that signal active infection

The fever from active TB is usually low-grade, not the high spike you get with flu. It often appears in the afternoon or evening and may return to normal at night, making it easy to miss if you do not take your temperature regularly. You might feel warm or flushed without realizing you have a fever.

Night sweats are often more noticeable. You wake up soaked, sometimes needing to change your clothes or sheets. These sweats happen because your immune system is fighting the infection and your body temperature regulation is disrupted. Night sweats alone can happen with many conditions, but combined with a persistent cough, they point toward TB.

Chest pain and breathing difficulty

Chest pain that worsens when you breathe deeply or cough happens when the infection inflames the lining around your lungs (the pleura). The pain is usually sharp and localized to one side. It may feel like a stitch in your side or a stabbing sensation.

Some people develop shortness of breath, though this is less common in early TB. If you have significant difficulty breathing, seek medical attention promptly. Chest pain combined with a cough lasting weeks is a strong signal to see a doctor even if you do not have fever.

Weight loss and loss of appetite

Unexplained weight loss is common in active TB. You may lose 5 to 10 pounds or more without trying, because the infection causes your body to burn more calories and your appetite drops. Food may taste different or unappetizing. This weight loss develops over weeks or months, not days.

Loss of appetite without weight loss can also occur. If you notice you are eating less than usual and have no clear reason—no stress, no diet change, no stomach problems—and you have other TB symptoms, mention it to your doctor. The combination of appetite loss with a persistent cough is worth investigating.

Symptoms that vary by where the infection spreads

Most TB infects the lungs, but the bacteria can spread to other parts of your body. Extrapulmonary TB causes different symptoms depending on the location. TB of the lymph nodes (the most common extrapulmonary form) causes swollen, tender nodes in the neck, armpits, or groin. TB of the bones or joints causes pain and swelling in the affected area. TB of the brain (meningitis) causes severe headache, stiff neck, confusion, and sensitivity to light.

These forms are less common than lung TB but are serious. If you have symptoms in areas other than your lungs and have been exposed to TB or have risk factors, tell your doctor about the exposure. Testing for TB should happen before other diagnoses are assumed.

Why symptoms take time to appear and what that means

TB bacteria grow slowly. From the time you are infected to the time symptoms appear can be weeks, months, or even years. This is why someone can have latent TB for decades without knowing. When symptoms do appear, they develop gradually—not overnight.

This slow progression means you may not connect your current symptoms to an exposure that happened months ago. If you remember being around someone with TB or suspect exposure, tell your doctor even if the contact was long ago. The timeline helps doctors decide whether to test you and what tests to order.

Frequently Asked Questions

Can you have TB without a cough?

Yes. Latent TB causes no symptoms at all. Extrapulmonary TB (infection outside the lungs) may not cause a cough—for example, TB of the lymph nodes causes swollen nodes but no respiratory symptoms. Testing is the only way to know if you have latent TB or TB in locations other than the lungs.

How long does it take for TB symptoms to show up?

It varies widely. Some people develop symptoms within weeks of infection; others take months or years. On average, symptoms appear within the first year after infection, but latent TB may never cause symptoms. If you know you were exposed, ask your doctor about testing even if you feel fine.

Is TB cough contagious?

Yes. When someone with active TB coughs, sneezes, or speaks, they release bacteria into the air. These droplets can infect others who breathe them in. You are most contagious in the first two to three weeks of active TB, before treatment starts. After starting treatment, contagiousness drops sharply within days.

What if I have a cough but no fever—could it still be TB?

Yes. Not everyone with active TB has fever. A persistent cough lasting more than three weeks is reason enough to see a doctor and mention TB as a possibility, especially if you have risk factors or known exposure. Fever is common but not required for a TB diagnosis.

Should I go to the emergency room if I cough up blood?

Yes. Coughing up blood is a sign the infection has damaged lung tissue and needs urgent evaluation. Go to the emergency room or call your doctor immediately. This does not always mean TB, but it is a serious symptom that requires prompt medical assessment.