T-Cell Lymphotropic Virus Type 1 (HTLV-1) is a retrovirus that primarily infects T-cells, a type of white blood cell crucial for the immune system. It is transmitted through bodily fluids, including blood, breast milk, and sexual contact. HTLV-1 is associated with several health conditions, including Adult T-cell Leukemia/Lymphoma (ATLL) and HTLV-1-associated myelopathy (HAM), which can lead to serious complications. Most people infected with HTLV-1 do not show symptoms, but the virus can remain dormant for years before causing health issues. Diagnosis typically involves blood tests to detect the virus or antibodies. There is currently no cure for HTLV-1, so management focuses on monitoring and treating associated conditions.