How can you tell if you have tuberculosis?

Tuberculosis: Clinically, patients with TB complain of cough (sometimes coughing up blood), weight loss, and night sweats. To diagnose it, we check sputum cultures. Chest x-rays show a wide variety of abnormalities.

Can't do it justice: in 400 characters of less. But here is a good overview by Mayo Clinic: http://www.mayoclinic.org/diseases-conditions/tuberculosis/home/ovc-20188556