Though it’s the most common STD in the United States, most people who have chlamydia are clueless. It doesn’t have symptoms — its infection can live in your vagina, cervix, urethra, rectum, or even your throat without warning. In post-menopausal women, its worst possible consequences are long-term pelvic pain, says the CDC, which is treatable. You should always get tested if you’re sexually active whether you suspect you have an STD or not.
According to the CDC, gonorrhea is another STD that’s hard to detect in both genders. Both men and women may experience painful urination if they have this disease. However, that, along with vaginal bleeding in women or discharge from the penis in men, could be mistaken for a bladder infection. Most won’t get tested for an STD because of this, so it’s important to use protection and get tested regularly if you’re sexually active.
11. Coronary artery disease
Heart disease and many other heart conditions progress with terrifying stealth. Coronary artery disease, a type of heart disease, occurs when the arteries that supply blood to your heart become narrow and hard, limiting your heart’s blood supply. Chest pain or tightness are the most common symptoms. But according to Cleveland Clinic, acid reflux, pneumonia, back problems, and even panic attacks and stress can also cause chest pain — so you might simply dismiss it. If you experience chest pain that lasts longer than five minutes, it’s likely heart-related, and you should seek medical attention as soon as possible.
12. Sleep apnea
According to the National Heart, Lung, and Blood Institute, sleep apnea occurs when the muscles in your throat relax while you’re sleeping. This prompts your brain to wake you up to restore normal breathing — but you usually don’t notice. It’s hard to make note of symptoms that are prominent only when you’re asleep, which is why many people don’t know they have this problem. This disease is more common in people who drink or smoke, and in those who are overweight or obese.
13. Deep vein thrombosis
When a blood clot develops in one of the veins of your lower leg or thigh, you may not even notice. If the clot comes loose, though, it could cause lung damage. You may experience tenderness, pain, redness or swelling in the affected area, but there’s a chance you won’t. The National Heart, Lung, and Blood Institute warns only half of people with DVT experience any of these symptoms. Avoid sitting for long periods of time to reduce your risk. Simply getting up and doing a few laps around the room is better than nothing.
14. Hepatitis C
Hepatitis C is a liver-targeting virus that can be either mild or severe. The World Health Organization says injections and drug use can spread hepatitis C, but so can sexual contact. Some people develop a minor infection that heals itself over time. However, it can become chronic, which causes liver damage. About 80% of people don’t show any symptoms at all, so good hygiene and regular STD testing are your best bet in preventing long-term problems.
Despite presenting with few to no symptoms, glaucoma is the second leading cause of blindness in the United States. According to All About Vision, this and associated eye conditions causes optic nerve damage. Since your optic nerve can’t carry information to your brain, you can lose peripheral vision, or go totally blind. You may experience pressure behind your eyes, a subtle signal that something is wrong, but not everyone with this condition will feel it getting worse.