Multiple sclerosis (or MS) and amyotrophic lateral sclerosis (or ALS) are both characterized by medical professionals as neurodegenerative diseases that strike at the central nervous system (or brain and spinal cord), thus impacting the function of nerves, muscles, and several other important bodily systems.

While MS and ALS have several similar traits, they also have some striking differences, such as:

1. Multiple sclerosis strikes the nerves
MS effects approximately 400,000 patients in the U.S. This disease attacks the central nervous system by progressively damaging the coating that surrounds and protects the nerves, thus impacting the brain to body messages that help guide bodily motor function.

2. ALS strikes the neurons
While amyotrophic lateral sclerosis, or Lou Gehrig’s disease, is also considered a progressive disease that damages the working order of the central nervous system, ALS patients experience damage to the brain’s neurons (which transmit signals that control overall bodily system function). ALS strikes approximately 16,000 U.S. individuals.

3. MS is considered an autoimmune disease
MS, like other autoimmune diseases, causes the immune system to launch an attack on normal, healthy tissues (in this case, the coating surrounding nerves).

4. ALS is not autoimmune related
ALS, on the other hand is considered a nervous system disorder, thought to be caused by either a chemical imbalance or an inherited genetic mutation.

5. MS is more common in women
MS strikes more than twice as many female vs. male patients. Women are typically diagnosed between the ages of 20- to 50-years old.

6. ALS strikes more males
ALS effects 20% more men vs. women with the average patients diagnosed at around 55-years old.

7. MS symptoms range from mild to severe
Many patients usually experience very mild symptoms to start, which can last many years without further decline or complete debilitation. Fewer MS patients experience rapid decline of nerve tissues, resulting in drastic loss of mobility. Late stage MS rarely leaves patients completely paralyzed.

8. Late stage ALS leads to complete paralyzation
The drastic decline of neurons (and commands to essential bodily functions) in ALS patients leads to the loss of several bodily systems (i.e., via the digestive, endocrine, lymphatic, muscular, nervous, renal, circulatory systems, etc.), and eventual paralyzation in the late stage of the disease.

9. MS symptoms often come and go…
While both diseases can cause similar symptoms (i.e., muscle spasms, fatigue, speech difficulties, trouble swallowing, etc.), MS can significantly impact a patient’s ability to taste, see, and feel (i.e., temperature, bladder control). Irritable mood and depression are also common in MS patients.

10. While ALS symptoms just get progressively worse
ALS causes eventually progresses through the entire body—starting with the mouth and throat, and moving outwards to the arms, legs, and feet. While ALS patients don’t typically experience a erratic mood or a decline in sensory (hearing, taste, feeling and smell) like MS patients; about 50% of ALS patients remain completely mentally intact, even when completely paralyzed. The other 50% may develop some form of cognitive decline (dementia).