I am having constant pain in me knees for the last 2 years. It goes up and down during the day and sometime no pain. Slight pain is also there in back side of the neck i.e. in the spine. I feel very lethargic during afternoon. Also have slight Constipation, gas and sore throat. The said symptoms are there for the last 2 years. All diagnostic tests like LFT, KFT, Vit B12, Vit D, Serum Ferritin, TSH, Sputum test for TB, Chest X-ray etc. and other tests have been done not once but twice and from 2 different labs as per the advise from doctors but nothing came up. At this point after reading and hearing so much, I do not understand what to do. I've heard that TB is hard to detect, so need to ask what is the sure test for TB or any other test that needs to be done for the said symptoms.