Tuberculosis
Also known as TB, Consumption
This article is general health information for the selected condition. It is not a diagnosis and does not replace clinical judgement. If you have questions or need treatment advice, please consult a qualified healthcare professional.
What is tuberculosis?
Tuberculosis is caused by Mycobacterium tuberculosis and most often affects the lungs, though it can involve almost any organ. It remains one of the leading infectious causes of death worldwide. Latent infection is common and symptomless but can reactivate later, which is why identifying and treating latent disease matters in high risk groups.
Causes
- Mycobacterium tuberculosis
- Airborne spread from a person with active pulmonary disease
- Prolonged close indoor contact
- Reactivation of latent infection when immunity falls
Symptoms
- Cough lasting more than three weeks
- Coughing up blood or sputum
- Chest pain
- Unintentional weight loss
- Drenching night sweats
- Fever
- Fatigue and loss of appetite
- Organ specific symptoms in extrapulmonary disease
Risk factors
- HIV infection
- Close contact with an active case
- Birth or residence in a high incidence country
- Immunosuppressive therapy including anti TNF agents
- Diabetes
- Malnutrition, homelessness and imprisonment
- Smoking and excess alcohol
Diagnosis
- Sputum smear microscopy and culture
- Rapid molecular testing including resistance detection
- Chest X-ray showing upper lobe changes or cavitation
- Tuberculin skin test or interferon gamma release assay for latent infection
- Biopsy for extrapulmonary disease
- HIV testing in all diagnosed patients
Treatment
- Standard six month regimen with rifampicin and isoniazid throughout
- Pyrazinamide and ethambutol in the first two months
- Directly observed or supported therapy to ensure adherence
- Longer tailored regimens for drug resistant disease
- Treatment of latent infection in high risk groups
- Contact tracing and public health notification
- BCG vaccination in high incidence settings
Self care
- Take every dose of the full regimen, which usually lasts six months
- Use a pill organiser and accept directly observed therapy if offered
- Expect urine and tears to turn orange on rifampicin, which is harmless
- Tell your doctor about all other medicines, since rifampicin interacts widely
- Use additional contraception, since rifampicin reduces pill effectiveness
- Cover coughs and ventilate rooms in the first weeks
- Eat well and avoid alcohol during treatment
When to see a doctor
Book an appointment if:
- Cough lasting more than three weeks
- Night sweats and unexplained weight loss
- Coughing up blood
- Contact with someone diagnosed with tuberculosis
- Yellowing of the skin or eyes during treatment
- Vision changes on ethambutol
Some symptoms need emergency care rather than an appointment. See the warning signs listed above.
Prevention
- BCG vaccination in high incidence settings
- Screening and treating latent infection in high risk groups
- Contact tracing around active cases
- Good ventilation in crowded settings
- Screening before starting anti TNF or other immunosuppressive therapy
- Prompt diagnosis and treatment to break transmission
Outlook
Drug sensitive tuberculosis is curable in the large majority when the full six month regimen is completed. Infectiousness usually falls within about two weeks of effective treatment. Incomplete treatment is the main driver of relapse and drug resistance, which requires longer, more toxic regimens with poorer outcomes.
Common questions
What is latent tuberculosis?
Infection without active disease. The person feels well, is not infectious, and has a normal chest X-ray, but the bacteria remain dormant and can reactivate later, particularly if immunity weakens.
How long does someone remain infectious?
Infectiousness usually falls substantially within about two weeks of starting effective treatment, provided the organism is sensitive to the drugs used and the person is taking them consistently.
Why does treatment last so long?
Mycobacteria grow slowly and some persist in a dormant state. Shorter courses leave survivors that cause relapse and encourage drug resistance, which is far harder and more expensive to treat.
References
Important: Dard AI is not a medical device and does not diagnose, treat, or replace clinician judgement. This article is general information only. Always consult a qualified healthcare professional about diagnosis and treatment, and seek emergency care for severe or rapidly worsening symptoms.