By understanding the typical progression of multiple sclerosis (MS) and learning what to expect, you can gain a sense of control and make more informed decisions about your day-to-day life.

MS occurs when the body’s immune system abnormally targets the central nervous system (CNS). The attack on the CNS damages the myelin and the nerve fibers that the myelin protects. The damage disrupts or distorts the nerve impulses being sent down the spinal cord.

People with MS generally follow one of four disease courses that vary in severity.

What are the 4 stages of MS?

Clinically isolated syndrome (CIS)

This is the first episode of symptoms caused by inflammation and damage to the myelin covering on nerves in the brain or spinal cord. Technically, CIS doesn’t meet the criteria for a diagnosis of MS, as it’s an isolated incident with only one area of demyelination responsible for symptoms.

If an MRI shows another episode in the past, a diagnosis of MS can be made.

Relapsing-remitting MS (RRMS)

The relapsing-remitting type of MS generally follows a predictable pattern, with periods in which symptoms worsen and then improve. Eventually, it may progress to secondary-progressive MS.

According to the National Multiple Sclerosis Society (NMSS), around 85 percent of people with MS are initially diagnosed with relapsing-remitting MS.

People with RRMS have flare-ups (relapses) of MS. Between the relapses, they have periods of remission. Over a few decades, the course of the disease is likely to change and become more complex.

Secondary-progressive MS (SPMS)

Relapsing-remitting MS can progress into a more aggressive form of the disease. Some of those with the relapsing-remitting form of the condition will go on to develop secondary-progressive MS. This generally happens within 10 years of the first diagnosis.

In secondary-progressive MS, people may still experience relapses. These are then followed by partial recoveries or periods of remission, but the disease doesn’t disappear between cycles. Instead, it steadily worsens.

Primary-progressive MS (PPMS)

Approximately 15 percent of people are diagnosed with a relatively uncommon form of the disease, called primary-progressive MS.

This form is characterized by slow and steady disease progression with no remission periods. Some people with primary-progressive MS experience occasional plateaus in their symptoms as well as minor improvements in function that tend to be temporary. There are variations in the progression rate over time.

“To read this article in its entirety click this link: Stages of MS.”