As for communicable diseases, both viral and bacterial, AIDS/HIV, tuberculosis, and malaria are the most common also causing millions of deaths every year (2014).
Another health issue that causes death or contributes to other health problems is malnutrition majorly among children. One of the groups malnutrition affects most is young children. Approximately 7.5 million children under the age of 5 die from malnutrition, and it is usually brought on by not having the money to find or make food (2014).
Bodily injuries are also a common health issue worldwide. These injuries, including broken bones, fractures, and burns can reduce a person's quality of life or can cause fatalities including infections that resulted from the injury or the severity injury in general (Moffett, 2013).
Some contributing factors to poor health are lifestyle choices. These include smoking cigarettes, and also can include a poor diet, whether it is overeating or an overly constrictive diet. Inactivity can also contribute to health issues and also a lack of sleep, excessive alcohol consumption, and neglect of oral hygiene (2013). There are also genetic disorders that are inherited by the person and can vary in how much they affect the person and when they surface (2013).
The one health issue that is the most unfortunate because the majority of these health issues are preventable is that approximately 1 billion people lack access to health care systems (Shah, 2014). It is easy to say that the most common and harmful health issue is that a lot of people do not have access to quality remedies.
Source : Wikipedia