Hiv is a virus that lives in human blood, sexual fluids, and breast milk. It weakens your immune system, so your body has a hard time fighting off common germs, viruses, fungi, and other invaders. Hiv doesn't live in saliva, tears, pee, or sweat -- so it can't be spread by casual contact with these body fluids.
It’s recommended that you test for hiv and other sexually transmitted infections (stis) at least once a year if you’re having sex, even if you always use protection. You might want to test more regularly than this, for example, if you are having sex with a new partner or feel you are more at risk. Groups who are more at risk are recommended to test more regularly. Testing every 3-6 months is often advised for men who have sex with men. Testing regularly helps keep your mind at rest, and if you test positive, it means you can start treatment quickly, protecting your health.