AMNA NAWAZ: An influx of migrants from earlier this year has overwhelmed some local governments on the U.S.-Mexico border.

In the border town of El Paso, nearly 38,000 migrants have arrived since January.

From the Cronkite School of Journalism in Phoenix, reporter Ariana Araiza introduces us to some of the volunteers stepping in to address migrants' health needs as they enter the United States.

ARIANA ARAIZA: For migrants at this El Paso, Texas, clinic, a medical exam could be a lifesaver.

Many have endured the perilous journey to get to the U.S. border.

DR. GLENN FENNELLY, Texas Tech University at El Paso: Many have pressing health care needs, needs for addressing mental health trauma and, in certain instances, addressing the trauma of literally falling off the wall.

ARIANA ARAIZA: That border wall is just a few blocks away.

Migrants have flooded into El Paso in the past few months.

Their sheer numbers have strained the city's social safety net.

Dr. Glenn Fennelly chairs pediatrics at Texas Tech University El Paso.

He carves out time to volunteer at this clinic.

DR. GLENN FENNELLY: Many have walked in shoes that don't have proper soles.

They have cactus needles in their feet.

And many have shared stories of abuse, trauma, rape.

ARIANA ARAIZA: Fennelly leads volunteers from Texas Tech's Border Health program.

The clinic provides free medical and mental health care for migrants.

SOROUSH OMIDVARNIA, Medical Student: Usually, the patients that we see are here for acute clinical needs.

ARIANA ARAIZA: Medical students like Soroush Omidvarnia say migrants health needs can be decades in the making.

SOROUSH OMIDVARNIA: Usually, they haven't had proper clinical care in their life even before coming to the United States.

So, it's really important for us to not just provide care for the condition that just brings them to us, but also find out what other needs they have.

ARIANA ARAIZA: These volunteers are part of a larger humanitarian effort to reinforce an El Paso medical system already overwhelmed by migrants.

On the Mexican side of the border, every day, thousands of migrants cram into Juarez after traveling sometimes hundreds or even thousands of miles.

Diana Urena is one of the lucky ones to make it into the United States.

But, first, she and her newborn son had to wait 16 days in Juarez before their entry was processed.

Robbed on the journey, she has no money, so she bides her time at this shelter in El Paso.

Urena and her family left Ecuador to escape gangs, making their way through the Darien Gap, a roadless jungle that's a dangerous passage point for migrants.

DIANA URENA, Ecuadorian Migrant (through translator): Can you imagine living through that?

In the jungle, you see dead people, you see everything.

On top of that, girls get raped.

I had that fear the whole journey for me and my daughter.

ARIANA ARAIZA: Solangi Uscategi and her family experienced similar trauma on their trip from Colombia.

Once here, Uscategi's husband was arrested on an immigration violation, leaving her and her daughters stranded.

SOLANGI USCATEGI, Colombian Migrant (through translator): I'm desperate.

I feel helpless and alone.

Without my husband and money, I feel helpless.

ARIANA ARAIZA: Back at the medical clinic, the volunteer team does their work under the radar.

The demand for health care is so high, the clinic would be overwhelmed if they advertised their services.

Dr. Fennelly says it's a small solution borne of necessity.

DR. GLENN FENNELLY: This is a humanitarian medical response to a manmade crisis.

ARIANA ARAIZA: For these volunteers, welcoming and healing is how they battle this crisis.

For the "PBS NewsHour," I'm Ariana Araiza with Cronkite News in El Paso.