10 questions you asked Dr. Google this year

(CNN) This year was full of headline-making health topics that left many people scratching their heads -- so they turned to Dr. Google for answers.

Among the top trending health-related questions searched on Google in the United States in 2016 were questions related to Zika, traumatic brain injuries and cupping, according to a list that Google spokeswoman Kara Berman sent to CNN in an email on Sunday.

A separate CNN analysis of health-related questions that were globally searched on Google this year included questions about Zika, among other topics, according to Google Adwords Keyword Planner.

"Examining what people search for provides a unique perspective on what they are currently interested in and curious about," according to the Google Trends team.

So, what exactly were you curious about in 2016? Here are some of the top health-related questions that were searched for this year, paired with a look back at CNN's coverage of each.

What is Zika virus?

Zika appears to top the global list of health-related questions searched for on Google in 2016, according to Google Keyword Planner.

In the data for the United States provided by Berman, the question "What are the symptoms of Zika?" appears as number 6 and "How long does Zika last?" appears as number 9.

Zika is a mosquito-borne virus that can be transmitted through mosquito bites, sex, possibly blood transfusion, and from a pregnant woman to her unborn baby, according to the Centers for Disease Control and Prevention.

There is no specific medicine to treat Zika and no vaccine to prevent it. Its symptoms can last for several days and include a fever, rash, joint pain, red eyes, muscle pain, and headache, according to the CDC. But a Zika infection during pregnancy can cause serious birth defects, including microcephaly, in which a baby's head is smaller than expected and the brain might not fully develop.

The virus was first identified in 1947. It wasn't until early 2015, however, when about 7,000 cases of Zika were seen in Brazil before the virus swept the world in 2016.

Mosquito-borne transmission cases of Zika soon were reported across the Americas and in parts of Asia and Africa. Travel notices were issued for some areas in the United States, Mexico, most of South America, Singapore, and Cape Verde, according to the CDC.

In February, the World Health Organization declared Zika to be a "public health emergency of international concern" as it spread "explosively" throughout the Americas. The CDC advised all pregnant women, and those trying to become pregnant, to avoid travel to any of the countries where Zika is active.

A total of 4,756 Zika cases have been recorded in the United States as of December 21, and 215 of those cases were locally acquired mosquito-borne cases, while 4,541 were travel-associated and one was laboratory acquired. Most of the locally transmitted Zika cases in the continental US occurred in South Florida and Brownsville, Texas, according to the CDC.

The first Zika-related death in the continental US was in Utah in July.

What is cupping and doping?

Another popular health question in 2016 was, "What is cupping," which topped the list of trending health questions in the United States, according to Berman's email.

Cupping is an ancient therapeutic practice in which round glass suction cups are warmed and placed on parts of the body that are experiencing muscle soreness. The cups create a partial vacuum, which is believed to relieve pain by stimulating muscles and blood flow.

The cups can leave behind dark red circular spots on the skin, which were seen on swimmer Michael Phelps and gymnast Alex Naddour during the 2016 Summer Olympics, sparking the curiosity behind many Google searches this year.

However, cupping wasn't the only big news that came out of the Summer Olympics. There was also doping, or taking drugs in order to enhance athletic performance.

"What is doping" appeared on the global list of top health-related questions, according to Google Adwords Keyword Planner.

Reports from the World Anti-Doping Agency have alleged that there has been a history of wide-scale doping by Russian athletes, which made headlines this year.

The International Olympic Committee even compiled a panel to determine which Russian athletes could be cleared to participate in the 2016 Summer Olympic Games and which should be banned from competing.

In December, the Kremlin said it would study these doping allegations thoroughly, but will "refrain from forming an emotional response to allegations of the 'state conspiracy,'" according to state news agency Sputnik.

What is TBI?

The fourth trending health-related question in the United States this year was "What is a TBI," according to Berman's email.

TBI, or traumatic brain injury, has been linked to sports injuries, combat injuries as diagnosed in war zones and physical violence.

However, TBI also made headlines this year when cell phone video of Keith Lamont Scott being fatally shot by Charlotte police was released in November and his wife is heard in the video screaming, "He has a TBI."

Scott's family said the injury, caused by a motorcycle accident, resulted in him stuttering or sometimes being forgetful.

A TBI can occur when a blow or jolt to the head causes damage to the brain, which can range in severity.

Some symptoms may appear immediately while others may not appear until days or weeks following the injury.

Symptoms include headache, loss of coordination, loss of consciousness, seizures, slurred speech, weakness or numbness, dilated eye pupils or the inability to awaken from sleep.

Questions that stand the test of time

The full list of the top 10 trending health questions in the United States this year also included questions about pregnancy, and whether certain illnesses are contagious:

What is cupping? Can you get pregnant while on your period? Is bronchiolitis contagious? What is a TBI? What causes yeast infection? What are the symptoms of Zika? How to get rid of cold sores fast? How long is pink eye contagious for? How long does Zika last? Can you get pregnant on birth control?

Popular health-related questions from around the world this year, according to Google Keyword Planner, included:

What is Zika virus What is ASMR (autonomous sensory meridian response) What is hash What is a hickey What is dopamine What is heterosexual What is an enema What is a lobotomy What is penicillin What is snuff What is quinine What is doping What is a fart What is a wet dream What is 420 What is angel dust