Nocebo Effect

A nocebo effect is said to occur when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have.

Consequences

One article that reviewed 31 studies on nocebo effects reported a wide range of symptoms that could manifest as nocebo effects including nausea, stomach pains, itching, bloating, depression, sleep problems, loss of appetite, sexual dysfunction and severe hypotension

Related

Placebo effect: An inert pill can cure health issues if the patient believes that it will.