Multiple sclerosis Multiple sclerosis (MS) is a disease that affects the spinal cord and the brain. There is not a single test to diagnose it, there are several tests. It is normally diagnosed by symptoms and signs, as well as laboratory tests. Multiple sclerosis can be difficult to diagnose because all the symptoms can be similar to other medical problems. According to the Diagnostic and Statistical Manual of Mental Disorders, the process of diagnosing multiple sclerosis involves three components to reaching a diagnosis. The first is the patient's history. The second is the neurological examination (tests of the nervous system and its functioning). The third is a variation of specialized procedures. These may include inspections of the spinal fluid (fluid that circulates through the spine), different types of X-rays, and many electrical tests. Another important feature of multiple sclerosis is that symptoms come and go in about two-thirds of MS patients. When these symptoms are present, they are called exacerbations. When they are not, it is an exacerbation....