(CNN) —  

It’s not just the fear of deportation that migrants face while crossing the Mexican border to the US. It’s the possibility of a slow, agonizing death while crossing a scorching desert or being crammed between 100 other people in an overheated semi truck.

So what drives these people to take such drastic risks? While some undocumented immigrants crossing the Mexico-US border are indeed Mexican, many embark on much longer journeys – from Central America and beyond.

By the numbers: Thousands of children flood US border from Guatemala, El Salvador

A snapshot of the countries they’re fleeing from shows the nightmares they’re trying to escape:

Honduras

Police hold a boy whose father was killed in 2016 by alleged gang members for refusing to pay them a "war tax" in Tegucigalpa, Honduras.
PHOTO: ORLANDO SIERRA/AFP/AFP/Getty Images
Police hold a boy whose father was killed in 2016 by alleged gang members for refusing to pay them a "war tax" in Tegucigalpa, Honduras.

Gross national income, per capita: $2,150

Population living in poverty: 60.9%

Life in Honduras: As the second-poorest country in Central America, Honduras “suffers from extraordinarily unequal distribution of income,” and rampant underemployment, the CIA World Factbook says.

Honduras is also the second-poorest country in Latin America.

Criminals have extorted Hondurans into paying an arbitrary “war tax” for their survival, and those who can’t pay are often killed.

Guatemala

Protesters march in Guatemala City in March to demand the resignation of Guatemalan President Jimmy Morales for "his inability to govern" and possible acts of corruption.
PHOTO: JOHAN ORDONEZ/AFP/AFP/Getty Images
Protesters march in Guatemala City in March to demand the resignation of Guatemalan President Jimmy Morales for "his inability to govern" and possible acts of corruption.

Gross national income, per capita: $3,790

Gross national income, per capita: $3,790

Population below poverty line: 59.3%

Life in Guatemala: Almost half of Guatemalan children under age 5 are chronically malnourished – “one of the highest malnutrition rates in the world,” the CIA World Factbook says.

Guatemala is the most populous country in Central America. It struggles with malnutrition, infant mortality, and contraceptive awareness and use.

El Salvador

A mother and her 3-year-old child from El Salvador await transport to an immigrant processing center after they crossed the Rio Grande into the US on July 24, 2014.
PHOTO: John Moore/Getty Images North America/Getty Images
A mother and her 3-year-old child from El Salvador await transport to an immigrant processing center after they crossed the Rio Grande into the US on July 24, 2014.

Gross national income, per capita: $3,920

Population below poverty line: 34.9%

Political strife or other conditions: El Salvador grapples with criminal gangs, and Salvadoran immigrants fleeing the country’s civil war started the brutal MS-13 gang decades ago in Los Angeles.

It’s also the most densely populated country in Central America.

Poor economic conditions and natural disasters contributed to many Salvadorans fleeing to the US in recent decades, according to the CIA World Factbook. “The remittances they send home account for close to 20% of GDP, are the second largest source of external income after exports, and have helped reduce poverty.”

Ecuador

A man surveyes the rubble in Portoviejo, Ecuador, after a 2016 earthquake killed more than 650 people.
PHOTO: JUAN CEVALLOS/AFP/AFP/Getty Images
A man surveyes the rubble in Portoviejo, Ecuador, after a 2016 earthquake killed more than 650 people.

Gross national income, per capita: $5,820

Population below poverty line: 25.6%

Political strife or other conditions: Ecuador’s politics have been so unstable in recent decades that three of the last four democratically elected presidents were ousted mid-term after protests.

While more Ecuadorians are climbing out of poverty, the country has been devastated by natural disasters, such as a 2016 earthquake that killed more than 650 people.

According to the CIA World Factbook, Ecuador also has a high risk for diseases such as typhoid fever, dengue fever and malaria.