This information is for people who have chronic obstructive pulmonary disease (COPD). It tells you about steroid tablets, a treatment used for COPD. It is based on the best and most up-to-date research.
Do they work?
Steroids may help if you have an attack of COPD (your symptoms suddenly get worse). But there isn't much of a benefit if you carry on taking them regularly. Taking steroid tablets regularly can also cause some serious side effects.
If you use a steroid inhaler, you're less likely to get side effects. If you need to take steroids regularly, your doctor will probably prescribe inhaled steroids rather than tablets.
What are they?
Steroids are medicines that help fight inflammation. They calm down and prevent swelling in the airways of people with chronic obstructive pulmonary disease (COPD). You can get them as tablets, or breathe them in through an inhaler.
The steroids used for COPD aren't the same drugs that some athletes and bodybuilders use. Those are called anabolic steroids. The steroids used to treat COPD are called corticosteroids. They are like chemicals your body makes to fight inflammation.
Prednisolone is a steroid tablet that's often used in the UK.
Doctors usually prescribe steroid tablets only if your symptoms, like breathlessness, suddenly get a lot worse.
The National Institute for Health and Clinical Excellence (NICE) is the organisation that decides which treatments should be available on the NHS. NICE recommends that doctors prescribe a short course of steroid tablets if you need hospital treatment for your COPD, or if you suddenly become much more breathless than usual. 
How can they help?
If you take steroid tablets for two to four weeks when your COPD is stable (you aren't having attacks), it can help your lungs work slightly better.  It might help you walk farther without getting breathless, and it might improve your other symptoms.
But there's no evidence from the research that taking steroid tablets will make a difference to your COPD in the long term.
How do they work?
Steroids may help because they reduce inflammation in your airways. This should make it easier for you to breathe.
Can they be harmful?
Yes. Steroids can cause serious side effects, so doctors usually prescribe them at the lowest dose possible, and for the shortest time possible.  Your doctor should explain the benefits and risks of your treatment before you start taking it. If you get any worrying symptoms while you're taking steroids, see your doctor straight away.
If you take steroid tablets for a long time, your bones may become weaker and more likely to break. This condition is called osteoporosis.
Taking steroid tablets for a long time can also cause a disease called diabetes. If you have diabetes, your body can't control the amount of sugar in your bloodstream.