National HIV Testing Day (NHTD) is an annual campaign to encourage people of all ages to "Take the Test, Take Control." Early HIV diagnosis is critical, so people who are infected can fully benefit from available life-saving treatments. Currently, almost 40 percent of people with HIV are not diagnosed until they already have developed AIDS. That can be up to 10 years after they first became infected with HIV. Finding out whether you are infected with HIV is the first step to improving your health and the health of your partners and your family.