Difficulties can compound exponentially. A study found that in the city of Hong Kong over half of the homeless people in the city (56%) had some degree of mental illness. Only 13% of the 56% were receiving treatment for their condition leaving a huge portion of homeless untreated for their mental illness.The issue of anti-homeless architecture came to light in 2014, after a photo displayed hostile features (spikes on the floor) in London, and took social media by storm. The photo of an anti-homeless structure was a classic example of hostile architecture, in an attempt to discourage people from attempting to access or use public space in irregular ways. However, although this has only recently came to light, hostile architecture has been around for a long time in many places. : 68  An example of this is a low overpass that was put in place between New York City and Long Island. Robert Moses, an urban planner, designed it this way in an attempt to prevent public buses from being able to pass through it. Healthcare
Health care for homeless people is a major public health challenge. When compared to the general population, people who are homeless experience higher rates of adverse physical and mental health outcomes. Chronic disease severity, respiratory conditions, rates of mental health illnesses and substance use are all often greater in homeless populations than the general population. Homelessness is also associated with a high risk of suicide attempts.
An example is the 1999 Athens earthquake in Greece, in which many middle class people became homeless, with some of them living in containers, especially in the Nea Ionia earthquake survivors container city provided by the government; in most cases, their only property that survived the quake was their car. Such people are known in Greece as seismopathis, meaning earthquake-struck.War or armed conflict can create refugees fleeing the violence. Whether they be either domestic or foreign to the country, the number of migrants can outstrip the supply of affordable housing, leaving some section of this population to be homeless. Foster care
Transitions from foster care and other public systems can also impact homelessness; specifically, youth who have been involved in, or are a part of the foster care system, are more likely to become homeless. Most leaving the system have no support and no income, making it nearly impossible to break the cycle, and forcing them to live on the streets. There is also a lack of shelter beds for youth; various shelters have strict and stringent admissions policies. Choice
Although uncommon, some choose to be homeless as a personal lifestyle choice. There are different reasons why someone would choose to become homeless. They may not want to contribute to a capitalist society, which includes having a job, spending and owing money, and paying taxes to the government. The main aspect of freeganism is anti-consumerism, and avoiding spending excessive amounts of money at all costs.