Black tea is a tree of the family of Teide which is derived from Assam. It is cultivated in India, Ceylon, Japan, Java and Kenya. Its leaves are rich in caffeine, tannin, aromatic substances. Black tea comes from those leaves which are fermented and roasted more times. It fights diarrhea, dysentery and nervous headaches. It is an excellent stimulant and tonic for body and brain. Black tea is recommended for people with thalassemia. In big and frequent use, it may cause weakness and insomnia.