Something as simple as borrowing a razor from another person can have serious health consequences. Some diseases -- like HIV and hepatitis -- are transmitted through blood, and you or the person with whom you share a razor may have nicked themselves without knowing and didn't sanitise the razor afterward. By sharing a razor, you may unknowingly expose yourself or others to disease or infection.
HIV, which can develop into AIDS, is one disease that can be transferred through sharing razors. HIV is transmitted through blood and other bodily fluids that a razor is likely to be contaminated with after each use. When it comes to HIV, contact -- especially of broken skin -- with the infected person's blood or other fluids can transmit the disease to another person. HIV and AIDS can be diagnosed through a test; talk to your doctor if you have concerns about being HIV positive.
Hepatitis B and C can be transmitted through sharing a razor with another person. Like HIV, infection can be caused by blood contact. There is a vaccine to prevent against hepatitis B, but not against hepatitis C. Both of these diseases can cause liver damage and have lifelong effects. If you suspect you might have contracted hepatitis, you should get tested and speak to your doctor about treatments.
Methicillin-resistant Staphylococcus aureus (MRSA) is a form of staph infection that is resistant to most antibiotics, and you can contract it by sharing razors. These infections usually cause the skin to become swollen, red and painful. You may also develop a fever, extra warm skin or fluid leakage from the area. You may be given medications to take or have the fluids drained from your skin at the doctor's office.
Sharing razors with someone else can also lead to folliculitis, an infection of your hair roots. Folliculitis appears to be a rash with pus coming from underneath the rash and visible hairs. Shaving should be stopped until the rash has healed and a new razor should be used. Antibiotics are generally not prescribed to heal folliculitis.