Sleeping sickness, or human African trypanosomiasis, is caused by the parasite Trypanosoma gambiense, transmitted by the tsetse fly found in sub-Saharan Africa. The life cycle involves a vertebrate host (humans) and an invertebrate host (tsetse fly), with symptoms ranging from fever and itching to confusion and sleep disturbances. Current treatment options include Bayer 205 and Lomidine, alongside preventive measures such as protective clothing and insect repellents.