Here are some of the most popular health-related questions searched for this year and the answers, as provided in CNN's coverage of each.
What are opioids? And '13 Reasons Why'?
Around the world, "What is keto diet?" "What are opioids?" "Why is addiction a disease?" and "13 Reasons Why" were among the most popular health-related queries on Google this year, according to Google Trends.
Many experts describe opioid addiction -- and addiction in general -- as a disease.
"Addiction is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences. It is considered a brain disease because drugs change the brain; they change its structure and how it works," according to the National Institute on Drug Abuse.
Also this year, adults and children alike were searching for more about the Netflix series "13 Reasons Why," based on bestselling author Jay Asher's 2007 young adult novel.
The series, which premiered in March, tells the fictional story of a teenage girl named Hannah Baker who leaves behind 13 audio recordings after ending her own life. She addresses each mysterious recording to a person who she says played a role in her decision to kill herself. Actress and pop star Selena Gomez is an executive producer of the show.
Even before the show debuted, some mental health experts noted that the show could pose health risks for certain young people who already have suicidal thoughts.
Just months later, researchers found that the controversial show's premiere correlated with Google searches tied to suicide awareness, prevention and ideation.
The search phrase "how to commit suicide" rose 26% above what would normally have been expected for that time; "suicide prevention" went up 23%; and "suicide hotline number" climbed 21%, according to a research paper published in JAMA Internal Medicine in October.
Other experts suggested that the show could provide an opportunity to discuss suicide risk with young people, including teaching them how to identify warning signs of depression or suicidal thoughts among their peers.
Another popular health question this year was "What causes hiccups?" which topped the list of trending health-related questions in the US, according to Grippi.
Hiccups are involuntary contractions of the diaphragm muscle that separates your chest from your abdomen, and those contractions may result from a large meal, alcoholic or carbonated drinks, or sudden excitement, according to Mayo Clinic.
The list of trending health-related questions ends with "What is lupus?" at No. 10.
Other celebrities who have been diagnosed with lupus include television personality Nick Cannon, Grammy-winning singer Toni Braxton, actress Kristen Johnston, retired US soccer team player Shannon Boxx and singer-songwriter Seal, who wears scars of the disease on his face.
The name "lupus," which means "wolf" in Latin, has been attributed to 13th-century physician Rogerius Frugardi, as he probably thought that scars from the disease resembled those from a wolf's bite, according to a paper published in the Journal of Cutaneous and Aesthetic Surgery in 2012.