Bullying is a problem that in the past was perceived to just impact kids. This was never true. However, more recently, workplace bullying and prevention programs have come into the spotlight, and adults, engaging online with both friends and strangers, may also fall prey to cyber-bullying. The link between chronic illness or disability and bullying are two-fold: children with health problems (ie. allergies, diabetes) or a disability (ie. cerebral palsy) are more likely to be bullied by peers , and adults who were bullied as children are more likely to develop chronic health problems.  The latter is due to increase in inflammatory compounds in the blood, caused by stress, which are contributors to many chronic diseases, including those you would typically attribute to inflammation, like arthritis and asthma, but also other health issues—notably heart disease and type 2 diabetes. These inflammatory markers were found more sharply elevated in the blood of those who had been bullied, even as many as ten years later. 
Children with chronic health issues may be bullied due to outward signs of their disease—for instance, children with hemophilia may be bullied due to needing to use crutches to allow healing of an affected limb from a bleed, missing school, or having a visible PICC line for treatments or blood transfusions.  Children with other medical issues may also miss school more frequently, whether due to illness or doctors appointments, or due to their symptoms at school, activity modifications, or treatments, such as those who need insulin pumps or injections, or feeding tubes. Bullying takes place not just in the classroom and playground, but online as well.  In a study in France and Ireland, of children with a chronic disease or disability, nearly 26 to 34 percent of children with a disability or chronic disease, aged 11, 13 and 15, had experienced bullying. 
Your role—as a parent, student, teacher, principal, employer, employee, etc.—will impact how you can help to prevent bullying. By learning respectful practices—such as sharing, taking turns, and learning how to talk out disagreements and problems—young, children carry valuable skills with them throughout their adult lives, which prevent kids both from becoming bullies and from not standing up to bullying for themselves or a friend. For principals or employers and teachers and employees, ensuring a bullying prevention plan and response strategy with consequences outlined, is created and implemented at your workplace is crucial—before an issue arise.
Parents should also ask their children regularly about how things are at school. Kids may not always report they are being bullied unless they are asked. As children with chronic illnesses or disabilities may be more prone to bullying, talking about bullying before it starts and how to respond may be important—and may be important for every child!
To learn about bullying prevention for different populations and for people of different roles, visit stopbullying.gov. As people with medical conditions may choose not to disclose their medical conditions for fear of bullying, wearing a medical ID bracelet or necklace can help notify emergency response staff in a discrete way about your medical needs.