Tuberculosis (TB) is a serious infectious disease caused by the bacterium Mycobacterium tuberculosis, primarily affecting the lungs but capable of spreading to other parts of the body such as the kidneys, spine, and brain. It spreads through the air when an infected person coughs, sneezes, or speaks, making it highly contagious in close or crowded environments.

Common symptoms of TB include a persistent cough lasting more than three weeks, chest pain, coughing up blood or sputum, fatigue, fever, night sweats, and weight loss. There are two main types — latent TB, where the bacteria remain inactive and cause no symptoms, and active TB, where the infection is active and contagious.

Diagnosis typically involves chest X-rays, sputum tests, and skin or blood tests. TB is treatable and curable with a proper course of antibiotics, usually taken for six months or longer. However, incomplete treatment can lead to drug-resistant TB (MDR-TB), which is more difficult to cure.

Preventive measures include vaccination with the BCG vaccine, early detection, regular screening in high-risk populations, and strict adherence to prescribed treatments. Awareness, proper hygiene, and strong public health measures are crucial in reducing the spread of tuberculosis worldwide.