Cases of sexually transmitted diseases in the U.S. reached a record high in 2017, according to a recent report from the Centers for Disease Control and Prevention. Nearly 2.3 million cases of STDs were diagnosed, over 200,000 more cases than the year before and the fourth consecutive year of higher rates.

Three of the sexually transmitted diseases that saw the highest rates of increase — chlamydia, gonorrhea and syphilis — are curable with antibiotics when diagnosed early. However, if they are left untreated and undiagnosed, these diseases can lead to organ failure, infertility and stillbirth. Chlamydia and gonorrhea are most common in young adults ages 16 to 24.

The CDC report doesn’t give a specific reason for the increased rates, but experts suggest the rising use of dating apps like Tinder, which makes it easy to find new partners, might be one reason. Decreased condom use also could be partly to blame. Factors like poverty, discrimination and drug use may play a role, too.

What can sexually active adults do to protect themselves from acquiring a sexually transmitted disease? Doctors recommend adults always use a latex condom properly, and don’t have sex with someone who exhibits any symptoms such as a rash or sores. Because all three of the diseases on the rise are asymptomatic, meaning no outward symptoms show, doctors recommend getting an STD test every six months if you are sexually active.

The CDC recommends all adults have a conversation with all of their potential sex partners about sexually transmitted diseases and about ways to protect themselves. It can be an uncomfortable conversation, but it’s important if you want to stay safe and healthy.