Symptoms

       TB or not TB?? 

        

You may not notice any symptoms of illness until the disease is quite advanced. Even then the symptoms -- loss of weight, loss of energy, poor appetite, fever, a productive cough, and night sweats -- might easily be blamed on another disease. Only about 10% of people infected with M. tuberculosis ever develop tuberculosis disease. Many of those who suffer TB do so in the first few years following infection, but the bacillus may lie dormant in the body for decades. Although most initial infections have no symptoms and people overcome them, they may develop fever, dry cough, and abnormalities that may be seen on a chest X-ray.

  

       

This is called primary pulmonary tuberculosis. It frequently goes away by itself, but in 50%-60% of cases, the disease can return. Tuberculosis pleuritis may occur in 10% of people who have the lung disease from tuberculosis. The pleural disease occurs from the rupture of a diseased area into the pleural space, the space between the lung and the lining of the abdominal cavity. These people have a nonproductive cough, chest pain, and fever. The disease may go away and then come back at a later date. People with weakened immune systems, TB bacteria may spread through their blood to various parts of the body.

 

This is called miliary tuberculosis and produces fever, weakness, loss of appetite, and weight loss. Cough and difficulty breathing are less common. Generally, return of dormant tuberculosis infection occurs in the upper lungs. Symptoms include common cough with a progressive increase in production of mucus and coughing up blood. Other symptoms include fever, loss of appetite, weight loss, and night sweats. About 15% of people may develop tuberculosis in an organ other than their lungs and 25% of these people usually had known TB with inadequate treatment. The most common sites includes lymph nodes, genitourinary tract, bone and joint sites, meninges, and the lining covering the outside of the gastrointestinal tract. 

Here are some mythbusters:

MYTH	Truth
Tuberculosis can be handed down in the family	No! Tuberculosis is an infectious disease which spreads by air droplets containing the bacteria entering the airway of a person.
Tuberculosis can be caused by smoking	Tuberculosis is caused by Mycobacterium tuberculosis, not smoking. Smoking can worsen tuberculosis.
BCG can protect you from developing TB	The vaccine can prevent severe forms of tuberculosis during childhood. But, it does not protect adults from developing active tuberculosis.
A person who has M. tuberculosis will have active tuberculosis	A tuberculosis infection does not always means you will end up having active TB. Whether a person will have active or latent TB, it depends on the state of health of the individual. Only 1/10 of the infected people will develop into active tuberculosis.
Tuberculosis will only affect the lungs	Tuberculosis can affect many parts of the body such as brain, kidneys, spine, bones and lymph nodes.
A positive Mantoux test means you have tuberculosis	A positive result of Mantoux test means that you are infected by a strain of Mycobacterium. It does not mean the illness is present.
People who have tuberculosis must stay in the hospital	Most people can stay at home to recover and can continue to work.

 And here's a little animation on TB symptoms :)

How does a doctor diagnose TB?

Doctor will complete the following tests to diagnose tuberculosis. You may not be hospitalized for either the initial tests or the beginning of treatment:

Chest X-ray:- most common diagnostic test that leads to the suspicion of infection. In primary TB, an X-ray will show an abnormality in the mid and lower lung fields, and lymph nodes may be enlarged.  Reactivated TB bacteria usually infiltrate the upper lobes of the lungs.

The  Mantoux skin test also known as a tuberculin skin test (TST or PPD test):- This test helps identify people infected with M. tuberculosis but who have no symptoms. A doctor must read the test. The doctor will inject 5 units of purified protein derivative (PPD) into your skin. If a raised bump of more than 5 mm (0.2 in) appears at the site 48 hours later, the test may be positive.

QuantiFERON-TB Gold test:- This is a blood test that is an aid in the diagnosis of TB that can help detect active and latent tuberculosis. The body responds to the presence of the tuberculosis bacteria. By special techniques, the patient's blood is incubated with proteins from TB bacteria. If the bacteria are in the patient, the immune cells in the blood sample respond to these proteins with the production of a substance called interferon-gamma (IFN-gamma). This substance is detected by the test. If someone had a prior BCG vaccination (a vaccine against TB given in some countries but not the U.S.) and a positive skin test due to this, the QuantiFERON-TB Gold test will not detect any IFN-gamma.

Sputum testing:- Sputum testing for acid-fast bacilli is the only test that confirms a TB diagnosis. If sputum (the mucus you cough up) is available, or can be induced, a lab test may give a positive result in up to 30% of people with active disease.