If you have been on steroids a long time then your adrenal glands stop producing cortisol, then when you stop taking steroids they don't always start back up and you end up with what is effectively Addison's disease.
Cushings is when you have an excess of cortisol and can be caused again by taking high doses of steroids for a prtracted period of time
Most people with Cushing syndrome have:
Round, red, full face (moon face)
Slow growth rate (in children)
Weight gain with fat accumulation on the trunk, but fat loss from the arms, legs, and buttocks (central obesity)
Skin changes that are often seen include:
Skin infections
Purple marks (1/2 inch or 1 centimeter or more wide), called striae, on the skin of the abdomen, thighs, and breasts
Thin skin with easy bruising
Muscle and bone changes include:
Backache, which occurs with routine activities
Bone pain or tenderness
Collection of fat between the shoulders and above the collar bone
Rib and spine fractures caused by thinning of the bones
Weak muscles, especially of the hips and shoulders
Women may have:
Excess hair growth on the face, neck, chest, abdomen, and thighs
Periods that become irregular or stop
Men may have:
Decreased or no desire for sex
Erection problems
Other symptoms that may occur include:
Mental changes, such as depression, anxiety, or changes in behavior
Fatigue
Headache
Increased thirst and urination
https://medlineplus.gov/ency/article/000389.htm