From the Affordable Care Act to flesh-eating bacteria to celebrities and elected officials battling physical and mental illness, it's been a tumultuous year for all things health.
Here is a look at the top 10 health stories of 2012, as chosen by the CNN Health staff.
1. Affordable Care Act upheld by the U.S. Supreme Court
In a 5-4 decision, the nation's highest court upheld the Patient Protection and Affordable Care Act, also known as Obamacare, on June 28.
Signed into law in March 2010, the sweeping law includes more than 90 specific changes to the nation's health care system. Some went into effect almost immediately, but the most dramatic changes won't take effect until 2014.
2. Georgia woman's battle with flesh-eating bacteria
Aimee Copeland, a then-24-year-old University of West Georgia graduate student, was visiting the Little Tallapoosa River, about 50 miles west of Atlanta, with friends when the homemade zip line she was holding snapped. She fell and got a gash in her leg that required 22 stables to close.
But Copeland's struggles were only beginning. Three days later, still in pain, she went to an emergency room. Doctors eventually determined she had necrotizing fasciitis, an infection caused by the flesh-eating bacteria Aeromonas hyrophila.
Copeland spent two months in an Augusta, Georgia, hospital, and doctors amputated her hands, leg and foot. She returned home in August to a 1,956-foot wing specially built for her.
3. Multi-state meningitis oubreak linked to steroid injections
A 19-state outbreak of non-contagious fungal meningitis sickened 620 people and killed 39, according to the latest update from the U.S. Centers for Disease Control and Prevention.
The cases were linked to tainted steroid injections distributed by the Massachusetts-based New England Compounding Center. "Several patients suffered strokes that are believed to have resulted from their infections," the CDC said. "The investigation also includes other infections from injections in a peripheral joint, such as a knee, shoulder or ankle."
The FDA said the compounding center was warned by its own environmental monitors of bacterial contamination of its facility months before the first cases were reported. The Massachusetts Board of Registration in Pharmacy voted to permanently revoke its license to operate in the state as well as the licenses of the company's three principal pharmacists.
4. West Nile Virus outbreak
While the case count of West Nile Virus illnesses was the highest reported through August 2012, this year's outbreak wound up falling short of levels seen in 2003, the worst-ever year for the virus.
The year's last update from the CDC showed a total of 5,387 cases of West Nile Virus and 243 deaths. Cases were reported in all lower 48 states, as well as the District of Columbia.
In 2003, 9,862 illnesses and 264 deaths were reported.
Texas was by far the hardest-hit state in 2012, with 954 cases and 76 deaths.
5. Robin Roberts' bone marrow transplant
"Good Morning America" host Robin Roberts, 51, revealed in June that after overcoming breast cancer, she was diagnosed with a rare blood disorder called myelodysplastic syndrome.
Roberts found a bone marrow match in her sister, Sally-Ann. Twenty-one days after undergoing a bone marrow transplant, Roberts was discharged from the hospital in October.
"I know it is your prayers and warm thoughts that have gotten me this far," she wrote in a post on "GMA's" website to her fans. "Each day I get stronger and stronger ... (E)ven in some dark moment, of which there are still a few, I now see that light at the end of the tunnel. This too really shall pass."
6. Hantavirus at Yosemite
Warnings were sent to Yosemite National Park visitors from 39 other countries in September after a potentially deadly hantavirus sickened some visitors to the park.
In all, eight people were infected and three died. Most became ill after staying at the park's popular Curry Village "tent cabins."