Refugee health is the field of study on the health effects experienced by people who have been displaced into another country or even to another part of the world, as a result of unsafe circumstances such as war or persecution. People who have been displaced can be affected by infectious diseases or some chronic diseases that are uncommon in the country in which they eventually settle. Mental health is an important consideration and can greatly impact people who are displaced. The health status of refugee's can be tied to factors such as the person who migrated's geographic origin, conditions of refugee camps or urban settings where they lived, and personal, physical, and psychological conditions of the person, either pre-existing or acquired while traveling from their homeland to a camp or eventually to their new home.

Major health concerns In general, people who come from other countries to more wealthier or developed countries are less likely to use general health services but are at greater risk of poor mental health and dying prematurely compared with native populations. People who are refugees are at a higher risk for contracting certain diseases or having other health problems due to factors such as poor nutrition, poor sanitation and lack of adequate medical care.

Non-communicable diseases A non-communicable disease is a medical condition that is not transmissible and not infectious. It is caused by individual and environmental behaviors. According to the WHO, these diseases lead to an estimated 40 million deaths per year, 70% of deaths worldwide. Development and control of these conditions is directly linked with nutrition and healthy behaviors. Non-communicable diseases have accounted for 19-46% of mortality from the top five refugee-producing countries in 2015. Reports indicate that more than half of Syrian refugee households (resettled in Lebanon) have a member suffering from a non-communicable disease.

Diabetes Diabetes is a group of chronic metabolic diseases that affect the body's use of blood sugar. There are two main forms of diabetes: type 1 and type 2. Type 1 diabetes is characterized by insulin deficiency and requires daily administered doses of insulin. Causes of Type 1 diabetes are unknown and are currently, not preventable. It is typically onset at an early age. Type 2 diabetes is characterized by the body's inability to properly utilize insulin. Type 2 diabetes is typically onset in adults and is linked with unhealthy behaviors. Another common form of diabetes is gestational diabetes. This occurs in pregnant women and does not necessarily lead to Type 1 or Type 2 diabetes permanently.

Refugees are at an increased risk of developing diabetes because of the tendency towards inadequate nutritional behaviors. According to the CDC, amongst Syrian refugees, there is a 6.1% prevalence of adult-onset diabetes. Iraqi refugees saw a 3% prevalence and Congolese refugees faced less than 1%. A literary analysis on diabetes risk amongst refugee populations suggests that increased diabetes risk among adult refugees may be associated with longer migration histories. The analysis also links increased diabetes prevalence with the transition from traditional, agricultural lifestyles with potentially protective foods, to urbanized, westernized lifestyles that come with migration.

Anemia Anemia is a condition in which an individual does not have enough healthy red blood cells. This will consequently lead to reduced oxygen flow to the body's organs. Most commonly, this is caused by not consuming enough iron. Anemia is used as a marker for overall micronutrient deficiency. Symptoms usually involve overall fatigue and tiredness, as a result of reduced oxygen flow. There are various treatments for anemia, including iron supplements and vitamin B supplements. Blood transfusions may also be used if blood production is low.

According to the CDC, "an evaluation of anemia prevalence in the Zaatari refugee camp and surrounding areas showed that 48.4% of children younger than 5 years of age, and 44.8% of women 15-49 years of age suffered from anemia". Amongst Congolese refugees, Sickle Cell Anemia (SCD) is of a much larger concern. In Central America, refugees coming from El Salvador, Guatemala, and Honduras show the highest incidence of anemia cases. The CDC reports that the prevalence for children under 5 years old is 30% in El Salvador, 47% in Guatemala, and 40% in Honduras. In Guatemala, 22% of pregnant women are also anemic. These cases are mostly credited to poor nutrition or a chronic parasitic infection.

Cardiovascular disease and hypertension Cardiovascular disease is a general term for various heart conditions such as coronary artery disease, cardiac arrest, arrhythmias, and many more. Hypertension is high blood pressure—this is usually defined as blood pressure over 130/80. Cardiovascular disease and hypertension are associated with poor nutrition/diet, sedentary lifestyles, and genetic risk factors.

Amongst Syrian refugees, 4.1% of adults suffered from cardiovascular disease and 10.7% suffered from hypertension. There is also substantial risk amongst Congolese refugees. According to the CDC, amongst Iraqi refugees in Jordan, 33% of those over 15 years of age had hypertension. Another 42% were pre-hypertensive. Bhutanese refugee adults had a 3% prevalence of hypertension, and nearly 1% prevalence of chronic obstructive pulmonary disorder.

Communicable diseases

Tuberculosis Tuberculosis (TB) is a bacterial infection that mainly affects the lungs. As an airborne disease, TB is spread via inhalation of the bacteria, which subsequently travel to the lungs and other body parts to manifest infection. Once a person is infected, TB can either become latent or active. If latent, the disease is asymptomatic and non-contagious; however, latent TB can become active at any point. Active TB is symptomatic and contagious. Either way, TB should be treated immediately, as untreated infections can be fatal.

An estimated third of the world's population is infected with Mycobacterium tuberculosis. This high incidence necessitates that those conducting the overseas exam (Panel Physicians) screen all refugees for TB and further test anyone suspected of having active TB. Screening for tuberculosis generally involves a tuberculin skin test, followed by a chest X-ray when necessary, and laboratory testing depending on those results. Anyone between the ages of 2 and 14, living in a country with a tuberculosis incidence rate of 20 or more cases per 100,000 people (as identified by the WHO), is required to have a tuberculin skin test. Those aged 15 and older must have a chest x-ray.

In the US, refugee individuals identified as having active tuberculosis must complete treatment before being permitted to enter. Upon arriving in the US, the CDC recommends that all refugees be screened for tuberculosis using a tuberculin skin test. A follow-up chest x-ray is required if the tuberculin skin test is positive, or if the refugee was identified as having TB (either Class A or Class B) in their overseas exam, or if they are infected with HIV.

Over 2 billion people are infected with TB worldwide. Specifically amongst refugee populations, the risk of contracting TB are higher than in the general population, as overcrowding and international travel is higher and more frequent. According to the WHO, as of 2016, the TB incidence rate in Syria is 17 per 100,000 people. Compare this to 3.1 per 100,000 people in the United States.

Infectious hepatitis There are multiple types of hepatitis, which most broadly can be described as viral infections of the liver. The most common types are viral hepatitis A, B, and C. Hepatitis B and C can result in chronic infections, while Hepatitis A is solely infectious. As such, Hepatitis A is also referred to as Infectious Hepatitis, and is caused by the Hepatitis A Virus (HAV). HAV can be spread directly or indirectly via fecal contact, causal contact, sexual contact, and foodborne or waterborne pathways. Because of this, refugee populations are more susceptible to this infection. According to a 2016 study conducted in Greece, the rate of Infectious Hepatitis amongst Syrian refugees in certain Greek facilities is 152 per 1,000 people; rates in refugees from Afghanistan and Iraq were much lower, at 8 per 1,000 and 9 per 1,000 people, respectively. The disproportionately higher rate in Syrian refugees can be attributed to the higher proportion of Syrian refugees in the camps, as compared to refugees from other countries of origin. There is no treatment for HAV infections, so hygienic intervention measures and vaccinations are of the highest priority in preventative measures. However, health care is often not prioritized in refugee populations and resources are limited, thus making it difficult to properly control the rate and spread of infection.

Hepatitis B Hepatitis B infection is endemic in Africa, Southeast Asia, East Asia, Northern Asia, and most of the Pacific Islands. According to the CDC, the rate of chronic infection among persons emigrating to the US from these areas is between 5% and 15%. Many states require or recommend that all refugees be screened for hepatitis B, and proceed with immunizations for all who are susceptible to this infection. In regions where the Hepatitis vaccine is not regulated, new infections occur predominately among infant and young children. As a result, 25% of people who become chronically infected as infants and 15% of people who become chronically infected at an older age die of Hepatitis B related health conditions.

Sexually transmitted infections Refugees can be at a higher risk for contracting sexually transmitted infections because of a lack of access to protection and/or treatment, as well as the circumstances of war and flight, making them subject to higher incidences of rape and sexual abuse. Refugees are regularly screened for syphilis, gonorrhea, chlamydia, and HIV infection when they relocate.

COVID-19 As the COVID-19 pandemic advances across the world, refugees are among the most vulnerable populations. Coronavirus disease 2019 is a highly-contagious respiratory and vascular disease, caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to social and economic conditions, resettled refugees face many of the same challenges that lead to poorer health for some racial and ethnic minority groups in the United States and in other countries. Refugees also face the challenges of a new healthcare system and finding health information they can understand. The density in population of refugee camps, in addition to lack of clean water, social distancing, and sanitation may impact exposure to COVID-19.

Parasitic infections