Multiple sclerosis is an autoimmune disease wherein through a mechanism that is yet to be understood, the immune system attacks the myelin sheath of the neurons. This sheath is the protective insulator of the neurons that allows for easy transfer of nerve impulses from one brain cell to another.

There are several forms of multiple sclerosis and for the most parts, the different kinds of MS are categorized under four types. They are as follows:

RRMS or Relapsing/Remitting Multiple Sclerosis
As its name suggests, this type is characterized by intermittent relapses (or exacerbation, or attacks of symptoms). During such relapses, new symptoms may arise while old symptoms subside or worsen. Since MS differs from one case to another, it is hard to distinguish which symptom will occur on a certain relapse and what new symptoms are to be expected. There really is no way of telling.

After the relapse, remission will follow. Remission is when the patient will undergo partial or complete recovery from the effects of the exacerbations.

The process of relapse may last anywhere from one day, two days, a week, a month, a year and so on. And the recovery period may come instantaneously or gradually. Most people who have this autoimmune disease first undergo RRMS which oftentimes hits at their early adulthood, though it is not rare to find cases when onset happens during middle age.

SPMS or Secondary Progressive Multiple Sclerosis
After the onset of the disease, patients may either feel no more symptoms or their symptoms will progressively worsen in between relapses. In this type, the patient may experience a mixture of good and bad days. Some patients who are still in the early phase of SPMS may still experience distinguishable relapses but as the disease worsens, remission lessens while the symptoms aggravate. At this point, no recovery may be expected. SPMS typically happens after a decade or so of having the condition.

PRMS or Progressive Relapsing Multiple Sclerosis
This type is still characterized by relapse and remission. However, with each relapse, the condition and symptoms worsen. It progressively follows a debilitating course.

PPMS or Primary Progressive Multiple Sclerosis
This can be considered as the basic type of multiple sclerosis, which follows the similar progression of other chronic diseases. The onset of symptoms leads on to continuous worsening of each attack. The sad part is, there are no remissions in this type. Instead, there may be periods when the severity of symptoms level off. Like with SPMS, this type is marked with good and bad days but the good days are just a little less inconvenient. This type differs from most types as it tends to affect people whose ages are anywhere from 30 to 50 years old and it is most typically seen among men, unlike secondary progressive and relapse/remitting types.

There are other forms of multiple sclerosis, some of them are sub-types of the more common ones while some of them are completely different from those already mentioned. Benign MS, for example, is a sub-type of RRMS wherein the onset is not marked by successive relapses and remissions. Instead, the patient may experience no symptom for as long as 15 years. Malignant MS, on the other hand, is a type where the period from onset to advanced severity happens in a very short period of time. Fortunately, this is a very rare type. Each type of MS requires different forms of treatments, therapies and handling. It is therefore very important to first know what the type is.