Multiple sclerosis (MS) is an autoimmune condition, which directly affects the central nervous system. There is no clarity on what causes MS, but some studies associate it with the Epstein Barr virus, vitamin D deficiency, and many environmental factors. However, not all kinds of MS are the same. Here are a few main types of multiple sclerosis:

1. Clinically isolated syndrome (CIS)
This is one of the foremost forms of multiple sclerosis. For a medical professional to label this condition as CIS, the neurological symptoms resulting from loss of myelin or inflammation should last for 24 hours. Over time, this form of MS might progress to other types. However, there are also some cases wherein the syndrome never aggravates.

2. Relapsing-remitting multiple sclerosis
Approximately 85 percent of people with multiple sclerosis are affected with this type. The first signs of this form of multiple sclerosis show in one’s early 20s or 30s. Following this, there may be symptom flare-ups or relapses repeatedly, followed by weeks, months, and even years of remission.

The severity of the attacks, the time between two relapses, and the degree of recovery may vary among patients. Most people with this type of multiple sclerosis see a deterioration in the condition and move to secondary progressive multiple sclerosis.

3. Primary progressive multiple sclerosis
This kind of MS progresses gradually yet steadily from its onset. The symptoms may remain constant in their intensity, but there are no remissions. In primary progressive multiple sclerosis, the patient may see a regular deterioration in their condition. However, throughout the duration of the disease, there may be differences in the degree of progression. Some might even see minor improvements, which are mostly temporary. Around 15 percent of the patients with MS suffer from this form, especially when the disease is in its early stages.

4. Secondary progressive multiple sclerosis
Secondary progressive multiple sclerosis is usually the stage after relapsing-remitting multiple sclerosis. In about 50 percent of people with relapsing-remitting multiple sclerosis, there has been a progression to secondary progressive multiple sclerosis in a duration of ten years, and this number rises to 90 percent in 25 years.

The condition is more or less similar to relapsing-remitting multiple sclerosis, but there may or may not be occasional relapses or minor remissions. Secondary progressive multiple sclerosis is difficult, and the disease only becomes more challenging to handle over time. The rate of progression differs from patient to patient.