Because HIV and HCV (Hep C Virus) are both spread through blood the risk of getting both through injecting drug use is higher.
People living with HIV are at greater risk of developing other infections such as Hep C because of a weakened immune system. This means that you your body is more susceptible to picking up an infection.
HIV and HCV are also transmitted in similar ways, which means that people who have HIV may be at higher risk of exposure to HCV. This is often referred to as co-infection.
Co-infection is higher in those who inject drugs and Hepatitis C infections are more serious in people with HIV and can lead to more severe damage of the liver.