Technically these are called “glucocorticosteroids,” or just “corticosteroids,” to differentiate them from anabolic steroids which athletes use (surreptitiously) to increase their muscles. Anabolic steroids have no real medical use. So when we speak of “Steroids” (for short), we mean the former.
There’s a natural steroid Cortisol produced in our adrenal glands. In complex ways, it regulates all our bodily functions. The natural amount of cortisol we produce is much lower than the doses of Steroid medications prescribed. Some common steroid medications include prednisone, hydrocortisone, dexamethasone, fluticasone, and many more
Steroids counteract inflammation. So they’re very useful in a very wide range of diseases and conditions. They can be given orally, intravenously (IV), applied to the skin, inhaled in the lungs, sprayed in the nose, or injected into muscle, under the skin, in the eye, around the spinal cord, & more.
Steroids provide enormous relief for all sorts of diseases. There’s almost no risk when applied to the skin or inhaled. When taken by mouth for 1-2 weeks, the only significant dangers are worsening of psychosis among persons with certain psychiatric conditions, worsening of existing heart failure, and outbreaks of disfiguring pustules in persons with psoriasis. But when even small-to-moderate doses are given orally for over 3-4 weeks, all sorts of side effects may begin to occur, including thinning of skin, wasting of bones and muscles, diabetes, stomach ulcers, and lots more.
One serious side effect of oral steroids if given for more than 2-3 weeks is interference with our immune system. So they can make us more likely to get a wide range of infections. They can also interfere with vaccines.
Also, after 3 weeks of steroids, our adrenal glands stop functioning, because they don’t need to. Constant exposure to steroid medications tells them it’s unnecessary to manufacture cortisol (their job). That’s not a problem, unless your body gets hit with significant physical stress, like an infection, major accident, heart attack, etc., times at when our system needs extra cortisol. If our adrenals can’t make it, we can suddenly go into shock. Anyone taking steroid medications for over 3 weeks needs to take extra doses in the event of sudden fever or any of the above (unless their steroid dose is really small). Ask your provider!
Also, if anyone taking steroids for over 3-4 weeks runs out of pills, their body can’t suddenly start producing cortisol again for a while. So then, too, you can go into shock. Depending on the steroid dose, and length of treatment, it can take weeks to months to gradually decrease the amount before stopping the treatment entirely. However, someone who only takes what we call a “steroid burst” for just 1-2 weeks can stop their medication abruptly without danger.
Just like everything in life, whatever seems good, can also be bad. So likewise with steroids.