Are normal healthy people susceptible to sepsis, or do you have to have cancer or something bad already?

Can happen to all: Yes, severe infection/ sepsis can happen to everybody. However, in immunocompromised people i.e. On chronic steroids or other immunosupressive agents, conditions that decrease immune system i.e. Cancer patients-especially on chemotherapy , hiv/aids, immunoglobulin deficiency etc- infection can become more severe and in a very rapid fashion sepsis can develop.

Either: Most patients who get septic do have an underlying disorder that weakens them and predisposes to severe infection. This does not have to be the case however. Sometimes individuals can get an infection in the community that is very severe and causes sepsis. ( bad pneumonia for example). This is less common however.

Anyone: Anyone can develop sepsis even if previously healthy since infections can occur in normal people. A classic example is severe pneumonia. You may be able to reduce your risk by having a well balanced diet that includes omega 3 fatty acids since this provides balance to your immune response to infection.

Can Be Healthy...: Normal, healthy people can get sepsis from a severe infection. You do not need to have an underlying disease to get sepsis.