Dreaming of having a disease does not necessarily mean that you actually have the disease. Diseases in your dream, cancer, AIDS, heart disease or the flu, indicate anxiety about a situation or fear that you have about actually getting the disease. It could also be a predictive dream where your unconscious is warning about the illness since you may not be conscious about the symptoms. If you dream about a sexually transmitted disease you may be feeling uneasy about your sexual activity. When you dream of having a heart problem whether you have a heart attack or stroke as well it symbolizes your heartbreaks. Dreaming of having cancer symbolizes an actual person or thing that is causing you to be uneasy. If you are having dreams of plagues or flu of some sort it could mean you anxious about the state of the world or maybe a change in your life. Dreaming of someone else having a disease could mean you are worried about that person or there is an actual problem with your health.