Generally, multiple sclerosis follows one of four courses:

• Relapsing-remitting, where symptoms may fade and then recur at random for many years. The disease does not advance during the remissions.
• Secondary progressive, which initially follows a relapsing-remitting course. Later on, it becomes steadily progressive.
• Primary progressive, where the disease is progressive from the start.
• Progressive relapsing, where steady deterioration of nerve function begins when symptoms first appear. Symptoms appear and disappear, but nerve damage continues. Few people have this course of MS.

Many people with MS do not follow one of these patterns exactly. The course is often hard to predict. Not only does it vary from person to person, but the pattern may change in an individual over time. MS may be more severe in men than women, particularly in middle-aged men who develop the disease.

MS usually progresses with a series of relapses that occur over many years (relapsing-remitting MS). In many people the first MS attack involves just a single symptom. It may be weeks, months, or years before you have a relapse. As time goes by, symptoms may linger after each relapse so you lose the ability to fully recover from the relapse. New symptoms often develop as the disease damages other areas of the brain or spinal cord.

Events that can indicate you may have a more severe progression of MS include:

• Frequent relapses during the first few years of the disease.
• Incomplete recovery between attacks.
• Early, lasting motor problems that affect movement.
• Many lesions that show up on an MRI early in the disease.

The duration of the disease varies. Most people who get MS live with it for decades. While people with MS often become disabled over time, the disease itself is rarely life-threatening and may not directly reduce your natural life span.

The majority of people who develop MS have a relapsing-remitting course; after about 10 years, approximately half of these people develop secondary progressive MS.

Some people have a few mild attacks from which they recover entirely. This is called benign MS.

Although rare, a small number of people die within several months of the onset of MS. This is called malignant or fulminant MS.

Pregnancy and MS

Since most people diagnosed with MS are women in their child-bearing years, questions about having children are common. Research shows that most couples in which one partner has MS are able to have children without MS affecting the pregnancy, labor, or delivery. Plus, MS does not increase the risk of miscarriage, birth defects, or low birth weight. Some women have fewer MS symptoms during pregnancy, then a temporary relapse after delivery. But pregnancy, delivering a baby, and early motherhood do not increase the risk of being disabled by MS over time.^{2, 3}