A person’s mouth is a good indication of not just oral health but also general health. So, not telling the truth about how often you floss or drink alcohol can cause underlying problems in the future. A strong relationship between dentist and patient is crucial to providing the best care possible. So, here are seven lies you should avoid telling at your next appointment.

Lie #1: “That doesn’t hurt.”

How they can tell: The proof is in your eyes. When people are in pain, their eyes will flinch or clench shut. Your body goes into a defensive mode. Dentists can also tell you’re hurting if your tongue and legs tighten.

What you should do: If what the dentist is doing hurts, speak up — especially if the pain is sharp. In that case, the dentist might use a topical anesthetic. And if you’re seeing the dentist for more than just a routine cleaning, call the office ahead of time and ask if you can take certain pain medications before your appointment.

Lie #2: “I hardly ever drink soda.”

How they can tell: The acid in soda can wear away the protective layer of enamel that coats the outside of your teeth and it does so, in a particular pattern. The lemonade and citrus fruits can do similar damage.

What you should do: Say no to soda, which has been linked to a host of health problems. As for sweet, acidic juices, it is advisable that you avoid sipping on them for long periods. It’s also a good idea to rinse your mouth with water afterward to remove any sugar and acid that can linger on your teeth and erode enamel.

Lie #3: “I don’t smoke.”

How they can tell: Tobacco is notorious for staining your teeth. Since the color of the stains can vary from person to person, a dentist might smell your clothes or examine your fingers for nicotine stains if he or she suspects you smoke.

What you should do: Quit — ASAP. Smoking doesn’t just put you at risk for lung cancer, it heightens your risk for pretty much any type of cancer, including those of the mouth and throat. Smokeless tobacco like snuff and tobacco chew isn’t safe, either: According to the Centers for Disease Control and Prevention, it can cause gum disease, tooth decay, and tooth loss. The CDC has a list of quit-smoking resources to help you kick the habit.

Lie #4: “I floss regularly.”

How they can tell: Brushing your teeth removes plaque above your gum line, but flossing can remove plaque from below your gums. So if your gums are inflamed, a condition called gingivitis, or gum disease, it’s a tip-off that you aren't flossing regularly or that you’re doing it wrong.

What you should do: Floss at least once a day. The American Dental Association recommends that people “guide” the string between their teeth (instead of snapping it up into the gums) and use gentle up-and-down motions to dislodge any food particles.

Lie #5: “I don't bite my nails .”

How they can tell: A dentist doesn’t need to look at your hands to figure this out. If there are chips and cracks in your teeth and wear caused by constant stress on your tooth are noticeable. It is a sign of nail-biting. It’s not the nails themselves that cause the damage, but the interaction that takes place between the top and bottom teeth.

What you should do: One thing you can do is keep your nails trimmed and filed. Taking care of your nails can help reduce your nail-biting habit and encourage you to keep your nails attractive and also better teeth.

Lie #6: “I don’t drink alcohol very often.”

How they can tell: Alcohol has a distinct smell, and what’s more, people who drink heavily tend to have very dry mouths. Alcohol interferes with the salivary glands and reduces saliva production.

What you should do: If you’re drinking heavily (that is, you have five or more drinks on the same occasion, on five or more days in the past month, according to the Substance Abuse and Mental Health Services), you may need to find professional help to quit. According to the American Cancer Society, about 7 out of 10 people with oral cancer are heavy drinkers.

Lie #7: “I don’t grind my teeth at night.”

How they can tell: Your teeth can acquire a worn  look from grinding. If you have headaches or muscle pain around your jaw, it’s a sign that you might have “nocturnal bruxism, a condition that’s also known as nocturnal tooth grinding. And while this may not count as an actual lie — because you’re probably unaware that you’re doing it — tooth grinding shouldn’t be ignored.

What you should do: You may need a bite guard or another type of dental device that can help protect your tooth enamel, or keep you from loosening a tooth. Your best bet is to discuss the possibility with your dentist.