context: If your multiple sclerosis flares up, steroids can treat your symptoms quickly. How do you know if you're having an MS flare? Here are some signs: Your symptoms suddenly worsen for a short time. You have symptoms you've never had before or notice old symptoms return. Your unusual symptoms last at least 24 hours or up to 48 hours. Your symptom flares don't result from an infection, stress, fever, or any other clear reason. For mild MS flares, you may not need steroids. Your symptoms will slowly get better on their own. If symptoms affect your ability to walk, see, or function, your doctor can prescribe a short-term dose of steroids. Steroids will work best to treat your MS flare if you start treatment within 14 days after the symptoms began. An MS flare is caused by inflammation in your nerves and myelin, the sheath of tissue around your nerves. Steroids help relieve your MS flare because they reduce the nerve inflammation. Steroids to treat MS flares are also called corticosteroids. There are different types, and all of these drugs have side effects. Steroids can shorten your MS flare. They ease your symptoms more quickly than if you just did nothing. But these medications don't affect the long-term course of your MS. Even if you take steroids, you'll recover from your flare gradually. It may take up to 6 months to get back to how you normally feel. The most common MS flare treatment is 1 gram of intravenous ( IV) methylprednisolone ( Solu- Medrol) daily for 3 to 5 days. It's a liquid steroid that's slowly dripped into your vein through a thin tube. Your IV treatment is also called an infusion. Dexamethasone ( Decadron) is another liquid steroid used to treat MS flares. You can get IV steroid infusions at your doctor's office, a clinic, hospital, or even at your home. Where you get IV steroid treatment may depend on your insurance coverage or what's available in your area. High-dose oral steroids like prednisone are another treatment for MS flares. These are pills or tablets. You'll start with a 1,250-milligram dose that tapers down over 1 to 2 weeks. Methylprednisolone pills are another option for MS flares. You'll take 500 milligrams of medicine for 5 days. Oral prednisone may work as well as IV steroids to ease MS flare symptoms. It costs less and doesn't require you to go to the doctor's office or clinic for infusions. Steroids make infections worse. Your doctor will try to make sure you don't have an infection before you start steroid treatment. You may need a urine test to be sure you don't have a urinary tract infection ( UTI), for example. Infection can trigger an MS flare in the first place. It's important to rule out that cause for your flare or worsened symptoms before you take steroids. What to tell your doctor: Let them know if you think you might be pregnant before you start steroids. IV methylprednisolone is a better option for pregnant women than oral prednisone. That's because your body processes the IV drug before it crosses over the placenta, the barrier that protects your baby. Be sure the doctor knows if you have diabetes because steroids can affect your blood sugar levels. Here are some possible, short-term side effects from taking steroids: Mood swings Swollen hands, ankles, or feet Bigger appetite Sleep problems like insomnia High blood pressure Upset stomach Cramps Back pain Headache Metallic taste in your mouth Flushed face Rash Heart palpitations Follow these tips to ease steroid side effects: Suck on hard candies or mints while you have your infusion to ease the metal taste. Watch how much salt you eat to ease water retention or puffiness. If steroids upset your stomach, try OTC treatments like ranitidine ( Zantac) or omeprazole ( Prilosec). Take steroid pills with food to protect your stomach. Let your doctor know if you can't sleep while on steroids. You may need a prescription sleep medicine. Take oral steroids in the morning to reduce their effect on your sleep later that night. Let your family and friends know that steroids may affect your mood for a short time. Ask them to support you during this time and understand that it's temporary. Hopefully, one course of steroids will treat your MS flare. If you feel ill after you're done with IV steroids, your doctor may prescribe 1 or 2 weeks of prednisone pills. You may also need a course of oral steroids if some of your symptoms came back after you're done with your infusion treatments.