What should you know about active TB and latent TB?

Latent infection can later become active, particularly when immune defences are weakened. Both states can be treated, but the medicines, infection-control steps and clinical follow-up may differ.

A positive TB blood or skin test indicates infection but cannot alone show whether disease is active. Clinicians combine symptoms, examination and chest imaging, then may test sputum or material from another affected body site. Active disease must be excluded before treatment for latent infection begins.

Active TB of the lungs often presents with a persistent cough, chest discomfort, sputum or blood when coughing, fever, night sweats, reduced appetite, weight loss or fatigue. TB outside the lungs can produce different findings, such as swollen lymph nodes, back pain or neurological symptoms. Latent TB itself causes no symptoms.

If active TB is suspected, contact a healthcare service promptly and tell them about the concern before arriving so they can arrange appropriate precautions. Follow instructions about masks, ventilation and limiting close indoor contact. The care team may also identify people who need testing after close exposure.

Treatment uses a planned combination of antibiotics selected for the type of TB, test results, other medicines and health conditions. Take every dose as directed and report side effects rather than stopping on your own, because interrupted or incomplete treatment can allow illness to persist and make the bacteria harder to treat. Latent TB treatment is preventive and should begin only after active disease has been ruled out.

Seek urgent medical care for coughing up more than small streaks of blood, severe breathlessness, chest pain, fainting, new confusion, a seizure, a severe headache with neck stiffness, or rapidly worsening weakness. These warning signs can reflect bleeding, breathing difficulty or TB affecting a critical body area.

Request prompt assessment for a persistent cough with fever, night sweats, weight loss or known close exposure to infectious TB. People with weakened immunity, pregnant people and young children should disclose that context when arranging care because it can affect the speed and type of evaluation.

Ask which findings support latent infection or active disease, whether TB involves the lungs, when you are considered non-infectious, and who among your close contacts needs screening. Confirm the medicine schedule, expected monitoring, possible interactions and which side effects require a same-day call.