Chances are, one of the first places you turn for quick information on everything from that new diet fad to a troubling rash to a cough that won’t quit is your handy search engine (although if you have a medical concern, there’s no substitute for an appointment with your doctor). So we asked the experts at Google to share the most popular health-related searches of the past year with us. “These top searched health-related questions are based on Google searches in the U.S. from January to November 2015,” says Simon Rogers, a data editor for Google’s News Lab. Here are the burning questions you searched for in 2015, along with answers from doctors and Health experts.

The question: “Is bronchitis contagious?”

Acute bronchitis is a chest cold that occurs when the bronchial tubes get irritated and inflamed, producing mucus that makes you cough. It may or may not be the result of a bacterial infection, which makes this question a difficult one to answer.

“For the most part, bacterial bronchitis and airway inflammation are not contagious per se,” says Health editorial advisory board member David L. Katz., MD, director of Yale University Prevention Research Center in New Haven, Conn. and founder of True Health Initiative. “Often, however, the precipitant for a bout of bronchitis is a viral infection of the upper airway—frequently called a cold—and these, of course, are contagious.”

In other words, patients should think of acute bronchitis as more a symptom of an illness rather than an illness itself. “Generally, bronchitis is a complication of an infection involving the upper respiratory tract,” explains Dr. Katz. “That infection is usually viral, and contagious. The complication of the infection—bronchitis—is not contagious, however. The subtlety here is that some viruses can cause bronchial inflammation even in the absence of prior vulnerability of bacterial infection, so the ‘no’ in this instance is a qualified no.”

In addition to acute bronchitis, more than 12 million Americans suffer from chronic bronchitis, which is one form of chronic obstructive pulmonary disease (COPD). This condition is typically brought on by cigarette smoking and is not contagious.

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The question: “Is pneumonia contagious?”

“The answer here is a qualified ‘yes’,” says Dr. Katz, explaining that most cases of pneumonia—an infection that causes the lung’s air sacs to fill up with fluid—are bacterial. So if you come in contact with someone suffering from bacterial pneumonia, it’s possible for those bacteria to be transmitted to you, although that might not necessarily cause you to develop pneumonia. There are also types of pneumonia that are viral rather than bacterial, and those viruses are more contagious.

In general, however, “pneumonia is not spread nearly as readily as viral infections of the upper airway,” says Dr. Katz. “It also stops being contagious when coughing stops, usually soon after the initiation of appropriate antibiotics.”

The question: “How much water should I drink?”

From coconut water to maple water to cactus water, trendy water-like beverages reigned supreme in 2015. When it comes to staying healthy and hydrated, though, nothing beats a plain-old glass of H2O. But how much do you really need each day?

“The easiest formula is to take your weight and divide it in half,” says Keri Gans, RDN, a New York City-based nutrition consultant and author of The Small Change Diet. “The number you get is the amount of water, in ounces, you should consume each day.” For example, if you weigh 140 pounds, you should be drinking about 70 ounces (or nine cups) of water a day. However, Gans adds that you should always take into account other factors, such as temperature, if you’re exercising, and if you’re pregnant or breastfeeding, in which case you’ll probably need more than that. “Another important thing to remember is that water isn’t the only way to meet your hydration needs,” says Gans. “Vegetables, fruit, and unsweetened beverages also count.”

The question: “How many calories should I eat?”

Unfortunately, there’s no one-size-fits-all answer to this question. “Calorie needs are based on age, height, weight, activity level, health status, and if you’re pregnant or breastfeeding,” says Megan Roosevelt, RD, founder and CEO of Healthy Grocery Girl. “For the most accurate calorie intake calculations, you should meet with a registered dietitian.”

Gans agrees: “Honestly, I never tell my patients to count calories,” she says. “I much prefer they focus their attention on creating well-balanced meals that include nutrient-rich foods and portion control.” However, Gans acknowledges that being aware of how many calories in general you’re consuming can help keep on you on track. She recommends that a 5’4″ woman consume between 1,400 and 1,600 calories a day if she’s slightly to moderately active and upwards of 1,900 calories if she’s very active. “But these numbers can still vary even more if we’re talking about an elite athlete or someone who is very sedentary,” she says.

Need help sticking to your goals? In July 2015, the NIH launched a new calorie calculator that uses the latest research to give you a personalized calorie count and exercise regimen to aim for.

The question: “What is lupus?”

Lupus, short for systemic lupus erythematosus, is a chronic autoimmune disease that affects more than 1.5 million Americans. Depending on its severity, the disease can impact the skin, kidneys, joints, heart, nervous system, and blood cells. Lupus is notoriously difficult to diagnose and is often confused with rheumatoid arthritis. One reason for this is that the symptoms vary widely from patient to patient and can include headaches, fatigue, joint pain, fever, and rashes (such as a sunburn-like “butterfly rash” that spreads across the face).

In the fall of 2015, pop star Selena Gomez revealed that her time away from the spotlight in 2014—which many tabloids attributed to drug and alcohol addition—was actually to treat lupus. “I was diagnosed with lupus, and I’ve been through chemotherapy. That’s what my break was really about. I could’ve had a stroke,” she said in an interview with Billboard. “I wanted so badly to say, ‘You guys have no idea. I’m in chemotherapy.’”

The question: “How far along am I?”

“Before we had blood tests and ultrasounds to help us determine how far along a pregnancy was, we relied on primitive information,” says Joshua U. Klein, MD, assistant clinical professor of OB/GYN and reproductive science at the Icahn School of Medicine at Mount Sinai Hospital in New York City. “Mainly, how large a woman’s abdomen was—a pretty inaccurate indicator—and when her last period was.” If a woman has a regular period, then the day of her last period is the most reliable (well, “semi-reliable,” as Dr. Klein puts it) method for knowing how far along she is. “For women who don’t have regular menstrual cycles, though, that kind of dating will be off.”

Thankfully, physicians today have more accurate methods for determining how far along a pregnancy is. “The primary instrument we use now is an ultrasound to look at fetus development,” says Dr. Klein. “In the first six weeks of pregnancy, you can also get a human chorionic gonadotropin (HCG) blood test that measures the level of the pregnancy hormone in your blood.”

Either way, knowing exactly when you conceived is important: “If you’re wrong, your OB could incorrectly calculate your due date,” says Dr. Klein. “And if it appears that you’re ‘late’ for that date nine months later, your doctor may induce the pregnancy prematurely without realizing it.”

The question: “When do you ovulate?”

In women of reproductive age, ovulation happens when an egg is released from the ovaries into the fallopian tubes, where it can be fertilized by sperm. For women with regular menstrual cycles, one of the easiest ways to monitor ovulation is by tracking your period. “If you have a period once a month, you’re ovulating once a month,” says Dr. Klein. “And the time of ovulation is usually in the middle of that cycle, approximately two weeks after the day of your last period.”

The average menstrual cycle is between 25 and 35 days, Dr. Klein says, but if you have longer intervals between periods—say, every two months—that means you’re only ovulating once every two months, too. If that’s the case for you, an at-home ovulation test can help you pinpoint exactly when ovulation occurs. “These tests typically have strips that can detect hormonal changes in the urine one to two days before ovulation,” says Dr. Klein. “They can help you get a pretty reliable handle on the one or two days in your cycle that you’re going to be ovulating, which is especially helpful if you’re trying to get pregnant.”

Other than monitoring your period or taking a test, can specific symptoms alert you to ovulation? “Some women know their bodies very well and come to recognize symptoms like abdominal pain, cramps, and breast tenderness around the time that they’re ovulating,” says Dr. Klein. However, because those symptoms can so often be indicators of something else, he cautions against relying on them entirely.

The question: “What is gluten?”

Gluten is a protein found in wheat, barley, rye. Interest in gluten-free diets continued to climb in 2015, as more and more people opted for gluten-free alternatives. If you have celiac disease or a gluten sensitivity, cutting gluten out of your diet is critical, since it can damage your intestines and trigger other health issues. But experts agree that eliminating gluten isn’t necessary for most people. A diet without gluten “can be very healthy, or it can be junk food,” says Dee Sandquist, RD, a Fairfield, Ohio-based nutritionist and spokesperson for the Academy of Nutrition and Dietetics. And in fact, there are plenty of reasons to keep eating whole grains, which are a great source of fiber and can help aid digestion, control weight, and lower cholesterol and blood pressure.

The question: “How long does the flu last?”

When you’re suffering from the seasonal flu, the only thing you can think about is getting better—and quickly. So when can you hope to see relief from symptoms like fever, cough, sore throat, and fatigue? “This varies to some extent with the strain each year, and obviously goes on longer if complications develop,” says Dr. Katz. “But the typical course of the flu is seven to ten days.” While you’re waiting for the virus to pass, prevent it from getting worse by drinking plenty of fluids, washing hands frequently, and eating vitamin D-fortified foods like orange juice and yogurt.

This article originally appeared on Health.com

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