Struggling small dairy farms in Kentucky. Segregation in charter schools. The challenges facing young asylum seekers in Europe. These are some of the feature stories that NBC News readers spent the most time on in 2018. Take a look back:

A woman walks by Recovery Point Charleston in Huntington, West Virginia. Raymond Thompson / for NBC News

In West Virginia, the state hit the hardest by the opioid epidemic, some desperate women have turned to sex work to fund their addiction.

“You literally live from moment to moment,” said Beth, one of the women who spoke to NBC News. “You don’t want to be sober because that’s when reality sets in.”

After Hurricane Katrina, Brad Pitt’s Make It Right Foundation built over 100 houses in the Lower Ninth Ward of New Orleans. But residents report that the houses are rotting and dangerous, the result of building done too quickly, with low-quality materials, and ill-planned designs.

One resident, Kamaria Allen, called the homes "a fool’s paradise.”

All Curtis Coombs wanted was to raise cows and run his family’s dairy farm in this slice of Kentucky hill country. But Coombs, like many of the small dairy farmers in the region, was unable to compete with big dairy farming businesses.

“It’s just hard to believe it’s over,” Coombs said. “As long as you was milking cows, you always thought there was a hope you'd get back to it.”

Montana's suicide rate is twice the national average — and that was before the state made cuts to mental health funding.

“We have a perfect storm when it comes to suicide,” said Karl Rosston, suicide prevention coordinator for Montana’s Department of Public Health and Human Services. “We have a lot of factors that are all happening at the same time.”

“Bias is in the air,” Alia Mcants said. “I didn’t realize that this was a systematic problem until after it happened to me.”

After delivering twins, McCants nearly died due to complications that caused her to hemorrhage. She later wondered whether her race influenced doctors' treatment of her.

The racial disparity in U.S. maternal mortality rates is one of the severest in women’s health, and experts believe implicit racial bias plays a role.

Iceland loves guns. And yet, unlike the United States, Iceland does not have a gun violence problem. One reason: Iceland's rigorous gun laws, which require background checks and classes before purchasing a firearm.

“It feels like somebody cares that you're getting a gun and what you're going to do with the gun," said Olaf Garðar Garðarsson, who lives on the outskirts of Reykjavik and spent more than a year studying to obtain a firearm. "So you're not going to buy a gun to do stupid things."

The frequency of robocalls has increased this year. Illustration by NBC News; Getty Images; Shutterstock

Robocalls, or automated calls that usually have a recorded message, increased by 50 percent from February to July of 2018. Some parts of the country were hit harder than others — see how your area code ranked.

Peter Ellenstein sits with several of his biological children. Dania Maxwell / for NBC News

Peter Ellenstein isn’t your ordinary father. He has more than 20 kids, all the result of his anonymous sperm donations, and he only began meeting them recently.

“It’s the best thing that’s ever happened to me,” he said. “Each kid so far that I’ve met is a whole other adventure and a whole new exciting thing in my life.”

Two pharmacies in Williamson, West Virginia, dispensed some 20.8 million painkillers over a decade. Antonio Zambardino / contrasto / Redux

“Every prescription I wrote was justified for the person who had gotten it,” said Dr. Katherine Hoover, the West Virginia who wrote more than 335,130 prescriptions for painkillers between December 2002 and January 2010.

Hoover wrote more opioid prescriptions than any other doctor in West Virginia during that time, but even though her colleagues faced charges, she was not prosecuted.

A wildfire burns in Alvdalen, central Sweden. Maja Suslin / EPA file

From heat waves and droughts to wildfires and superstorms, the globe has seen an increase in extreme weather — and now scientists are able to explain how climate change is playing a role. Here's how the science works.

Twins Zyler and Kadyn are being raised as “theybies,” brought up without a gender designation from birth — part of a growing trend of raising children outside of gender norms.

"I’m hoping that they’ll grow up and be supportive of other people and who they are and how they feel and really confident and happy in who they are themselves," said Julia Sharpe, the twins' mother.

A WhatsApp-Reliance Jio representative explains how to use WhatsApp messenger to a woman on the outskirts of Kolkata, India. Rupak De Chowdhuri / Reuters file

On the popular messaging service WhatsApp, fake news stories and rumors spread like wildfire, often with deadly consequences.

"It presents a new challenge for stopping the influence of disinformation on the public,” said Joan Donovan, media manipulation research lead at the nonprofit Data & Society.

Khasim, a refugee from Afghanistan, poses for a photograph while concealing his identity on a side street off Omonia Square in central Athens, Greece. Marko Drobnjakovic / for NBC News

“If I do not go to Germany, I’ll kill myself,” said Khasim, a young asylum seeker who was trapped in Athens, Greece. A former dental student, Khasim left Afghanistan for Europe to find employment, but got stuck in Athens, where he sold sex to get by.

Two years ago, Greece closed its northern border into Europe, stranding more than 50,000 asylum seekers and refugees in Greece, including many young men like Khasim.

Lake Oconee Academy is equipped with golf courses, a piano room and more than a dozen Advanced Placement courses. And like many other charter schools across the country, Lake Oconee has implemented policies that critics say make it difficult for lower-income families to enroll.

“It’s like a black and white thing, who has money and who doesn’t have money,” said Kim Smith, a black mother who was unable to send her children to the school because it does not offer bus transportation.

Bedford Hills Correctional Facility in New York is home to the nation’s longest-run prison nursery, which allows mothers who started their sentence pregnant to bond with their babies while behind bars.

“To be in prison with my baby every day for the past 10 months has been a beautiful gift,” said Lindsay Landon, one of the mothers in the program.