Tuberculosis is spreading by air, if an infected person coughs sneezes or shouts, the germs spreading into the air. By inhaling them other people get infected.

At the thoracic X-ray appear granulomas (granular tumors) in the lungs.

Most people's immune system contains the primary infection, but some do not have this particularity, and so, the disease may occur within weeks after the primary infection.
Some people shed the TB germ into their lungs for years and at some moment the germs could activate and the infection could manifest.

The easiest to infect are the children and people who have a weakened immune system (those undergoing chemotherapy, those who had an organ transplant and now take immunosuppressive drugs, and those infected with HIV).

To prevent TB in children doctors give them shots of the bacillus Calmette Guerin (BCG) vaccine.

The risk of catching TB increases with the frequency of contacting other infected people, with miserable living conditions and with poor nutrition.

Lately there has been noticed an increase of TB cases in US, probably because of the increased number of people infected with HIV, the increased number of homeless people and of the appearance of drug resistance (caused by an incomplete TB treatment).

In US there are 10 cases of TB per 100000 people and those infected with AIDS are among them, due to their weakened immune system.

Some of the TB symptoms are cough for a long period of time, fever, night sweats, loss of weight and appetite, chest pains and breathing difficulties.

To diagnose the infection with TB there are some tests to be done.
One way to diagnose TB is by performing a skin test called the intra-dermal reaction of tuberculin. The person that is suspected to be or to have been infected with TB is considered to have developed a hypersensitivity to the TB germ.

The test consists in injecting into the skin a purified protein derived from the TB germ. After more then 48 hours the skin area will present a bump. If the bump is large, the test is considered to be positive, meaning that the TB infection has occurred.

Even if the test is negative, it should be repeated after a while, because the test is not a 100 percent accurate.

Another method of diagnosing TB is performing a thoracic X-ray that will show the affected lung areas.

And last, but not the least, is the sputum test. If the suspected person coughs, doctors take the sputum and with the help of the microscope they search for the TB germs in it.

Also doctors can perform a Bronchoscopy, a Thoracocentesis and rarely, biopsy of the affected tissue.

For the treatment to be effective, patients must take their prescribed dugs during all the period of time they were advised by the doctor, otherwise they could get multiple organ complications and even die.

By following all the doctor's indications, one can cure in about 6 to 9 months of TB and get back to its normal life.