Psychological reactions such as insomnia and irritability are common, but they are certainly not the only prednisone side effects. Some of these adverse consequences, such as osteopenia, diabetes or glaucoma, appear only after long-term use of the drug. Others, such as confusion, high blood pressure or a drop in potassium, can occur on a shorter time frame. The most serious prednisone side effects that may happen within a week or two of use are dangerous blood clots (deep vein thrombosis), blood infections (sepsis) and bone fractures (Waljee et al, BMJ , April 12, 2017 ). We offer a more complete list below.