Lung Disease & Respiratory Health Center

Understanding Tuberculosis -- Diagnosis and Treatment

How Do I Know If I Have Tuberculosis?

The Mantoux skin test -- -- also commonly known as PPD and performed in a doctor's office or health department -- is a reliable detector of TB in most people.  A small amount of liquid material is injected just under the top layer of skin on your arm. After two to three days, a doctor or nurse will evaluate your arm to see if the test is positive. If it is, you will have a hard, red welt at the injection site. A positive result means you have been infected with TB, even if the infection is not active.

There are also two blood tests that can be used in certain cases to diagnose TB.  An X-ray of your lungs helps reveal whether the disease is active.

Whether or not your TB is active, you should be regularly monitored by your doctor.

What Is the Treatment for Tuberculosis?

Treatment for TB depends on whether it is active or latent.

Latent TB Infection

If you're infected with TB but don't have the active disease, your doctor will go over your risk factors for developing active TB and will discuss your treatment options. An antibiotic called isoniazid (INH) is often prescribed to help prevent the dormant infection from becoming active.

Your doctor will likely give you a daily or twice weekly dose of isoniazid and evaluate you regularly to ensure that you're tolerating the drug without major side effects. The risks of taking INH increase with age. In addition, your doctor may recommend vitamin B6 (pyridoxine) to prevent specific side effects of INH.

Active TB Disease

If you have active TB disease, your doctor will give you several antibiotics to treat the infection and to help prevent resistant bacteria from emerging in your body. You may be taking a combination of antibiotics that may include isoniazid, rifampin, pyrazinamide, or ethambutol for 6 to 12 months. Because active TB disease can be fatal if left untreated, regular monitoring and treatment by a doctor are crucial.

Multidrug-Resistant TB

A form of TB, called multidrug-resistant TB,  is caused by strains of the tuberculosis bacteria that, through mutation, have developed the ability to resist two or more antibiotic drugs. Worldwide, almost half a million people develop this form of TB annually, and about 150,000 die from this disease. 

An even newer form of TB, called extensively drug-resistant TB, resists almost all TB treatments. Fortunately, this form of TB is still relatively rare. Most cases of TB are still highly treatable if the patient follows the full course of antibiotic treatment.