A negative TB skin test means that the person in question didn't mount an immune response to the antigen placed under the skin, according to the Centers for Disease Control and Prevention. A negative test means that the person is unlikely to have latent or active tuberculosis.
TB symptoms include a cough lasting for more than three weeks, chest pain with breathing or coughing, and coughing up blood, notes Mayo Clinic. Other constitutional symptoms include night sweats, unintentional weight loss, fever, chills and appetite loss.
Tuburculosis is an infectious disease that targets the lungs, explains Mayo Clinic. The infection is spread through the air via coughing and sneezing. Many strains of TB are resistant to common antibiotics, so individuals with the disease often require treatment with several drugs over an extended period of time.