Although your body may harbor the bacteria that cause tuberculosis, your immune system often can prevent you from becoming sick. For this reason, doctors make a distinction between:
Latent TB. In this condition, you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called inactive TB or TB infection, isn’t contagious.
Active TB. This condition makes you sick and can spread to others.
Signs and symptoms of active TB include:
Unexplained weight loss
Loss of appetite
Tuberculosis usually attacks your lungs. Signs and symptoms of TB of the lungs include:
Coughing that lasts three or more weeks
Coughing up blood
Chest pain, or pain with breathing or coughing
Tuberculosis can also affect other parts of your body, including your kidneys, spine or brain. When TB occurs outside your lungs, symptoms vary according to the organs involved. For example, tuberculosis of the spine may give you back pain, and tuberculosis in your kidneys might cause blood in your urine.
When to see a doctor
See your doctor if you have a fever, unexplained weight loss, night sweats and a persistent cough. These are often signs of TB, but they can also result from other medical problems. Your doctor can perform tests to help determine the cause. TB can be diagnosed by your primary care doctor or by a doctor who specializes in lung diseases (pulmonologist) or by an infectious disease specialist. If you don’t have a doctor, your local public health department can help.